#Copyright ReportLab Europe Ltd. 2000-2019
#see license.txt for license details
# $URI:$
__version__='3.5.34'
__doc__='''Gazillions of miscellaneous internal utility functions'''

import os, sys, time, types, datetime, ast
from functools import reduce as functools_reduce
literal_eval = ast.literal_eval
try:
    from base64 import decodebytes as base64_decodebytes, encodebytes as base64_encodebytes
except ImportError:
    from base64 import decodestring as base64_decodebytes, encodestring as base64_encodebytes
from reportlab import isPy3
from reportlab.lib.logger import warnOnce
from reportlab.lib.rltempfile import get_rl_tempfile, get_rl_tempdir, _rl_getuid
from . rl_safe_eval import rl_safe_exec, rl_safe_eval, safer_globals

class __UNSET__(object):
    @staticmethod
    def __bool__():
        return False
    @staticmethod
    def __str__():
        return '__UNSET__'
    __repr__ = __str__
__UNSET__ = __UNSET__()

try:
    import cPickle as pickle
except ImportError:
    import pickle

try:
    from hashlib import md5
except ImportError:
    import md5

try:
    import platform
    isPyPy = platform.python_implementation()=='PyPy'
except:
    isPyPy = False

def isFunction(v):
    return type(v) == type(isFunction)

class c:
    def m(self): pass

def isMethod(v,mt=type(c.m)):
    return type(v) == mt
del c

def isModule(v):
    return type(v) == type(sys)

def isSeq(v,_st=(tuple,list)):
    return isinstance(v,_st)

def isNative(v):
    return isinstance(v, str)

#isStr is supposed to be for arbitrary stringType
#isBytes for bytes strings only
#isUnicode for proper unicode
if isPy3:
    _rl_NoneType=type(None)
    bytesT = bytes
    unicodeT = str
    strTypes = (str,bytes)
    def _digester(s):
        return md5(s if isBytes(s) else s.encode('utf8')).hexdigest()

    def asBytes(v,enc='utf8'):
        if isinstance(v,bytes): return v
        try:
            return v.encode(enc)
        except:
            annotateException('asBytes(%s,enc=%s) error: ' % (ascii(v),ascii(enc)))

    def asUnicode(v,enc='utf8'):
        if isinstance(v,str): return v
        try:
            return v.decode(enc)
        except:
            annotateException('asUnicode(%s,enc=%s) error: ' % (ascii(v),ascii(enc)))

    def asUnicodeEx(v,enc='utf8'):
        if isinstance(v,str): return v
        try:
            return v.decode(enc) if isinstance(v,bytes) else str(v)
        except:
            annotateException('asUnicodeEx(%s,enc=%s) error: ' % (ascii(v),ascii(enc)))
        
    def asNative(v,enc='utf8'):
        return asUnicode(v,enc=enc)

    uniChr = chr

    def int2Byte(i):
        return bytes([i])

    def isStr(v):
        return isinstance(v, (str,bytes))

    def isBytes(v):
        return isinstance(v, bytes)

    def isUnicode(v):
        return isinstance(v, str)

    def isClass(v):
        return isinstance(v, type)

    def isNonPrimitiveInstance(x):
        return not isinstance(x,(float,int,type,tuple,list,dict,str,bytes,complex,bool,slice,_rl_NoneType,
            types.FunctionType,types.LambdaType,types.CodeType,
            types.MappingProxyType,types.SimpleNamespace,
            types.GeneratorType,types.MethodType,types.BuiltinFunctionType,
            types.BuiltinMethodType,types.ModuleType,types.TracebackType,
            types.FrameType,types.GetSetDescriptorType,types.MemberDescriptorType))

    def instantiated(v):
        return not isinstance(v,type)

    from string import ascii_letters, ascii_uppercase, ascii_lowercase

    from io import BytesIO, StringIO
    def getBytesIO(buf=None):
        '''unified StringIO instance interface'''
        if buf:
            return BytesIO(buf)
        return BytesIO()
    _bytesIOType = BytesIO 

    def getStringIO(buf=None):
        '''unified StringIO instance interface'''
        if buf:
            return StringIO(buf)
        return StringIO()

    def bytestr(x,enc='utf8'):
        if isinstance(x,str):
            return x.encode(enc)
        elif isinstance(x,bytes):
            return x
        else:
            return str(x).encode(enc)

    def encode_label(args):
        return base64_encodebytes(pickle.dumps(args)).strip().decode('latin1')

    def decode_label(label):
        return pickle.loads(base64_decodebytes(label.encode('latin1')))

    def rawUnicode(s):
        '''converts first 256 unicodes 1-1'''
        return s.decode('latin1') if not isinstance(s,str) else s

    def rawBytes(s):
        '''converts first 256 unicodes 1-1'''
        return s.encode('latin1') if isinstance(s,str) else s
    import builtins
    rl_exec = getattr(builtins,'exec')
    del builtins
    def char2int(s):
        return  s if isinstance(s,int) else ord(s if isinstance(s,str) else s.decode('latin1'))
    def rl_reraise(t, v, b=None):
        if v.__traceback__ is not b:
            raise v.with_traceback(b)
        raise v
    def rl_add_builtins(**kwd):
        import builtins
        for k,v in kwd.items():
            setattr(builtins,k,v)
else:
    bytesT = str
    unicodeT = unicode
    strTypes = basestring
    if sys.hexversion >= 0x02000000:
        def _digester(s):
            return md5(s).hexdigest()
    else:
        # hexdigest not available in 1.5
        def _digester(s):
            return join(["%02x" % ord(x) for x in md5(s).digest()], '')

    def asBytes(v,enc='utf8'):
        if isinstance(v,str): return v
        try:
            return v.encode(enc)
        except:
            annotateException('asBytes(%s,enc=%s) error: ' % (repr(v),repr(enc)))

    def asNative(v,enc='utf8'):
        return asBytes(v,enc=enc)

    def uniChr(v):
        return unichr(v)

    def isStr(v):
        return isinstance(v, basestring)

    def isBytes(v):
        return isinstance(v, str)

    def isUnicode(v):
        return isinstance(v, unicode)

    def asUnicode(v,enc='utf8'):
        if isinstance(v,unicode): return v
        try:
            return v.decode(enc)
        except:
            annotateException('asUnicode(%s,enc=%s) error: ' % (repr(v),repr(enc)))

    def asUnicodeEx(v,enc='utf8'):
        if isinstance(v,unicode): return v
        try:
            return v.decode(enc) if isinstance(v,str) else str(v)
        except:
            annotateException('asUnicodeEx(%s,enc=%s) error: ' % (repr(v),repr(enc)))

    def isClass(v):
        return isinstance(v,(types.ClassType,type))

    def isNonPrimitiveInstance(x):
        return isinstance(x,types.InstanceType) or not isinstance(x,(float,int,long,type,tuple,list,dict,bool,unicode,str,buffer,complex,slice,types.NoneType,
                    types.FunctionType,types.LambdaType,types.CodeType,types.GeneratorType,
                    types.ClassType,types.UnboundMethodType,types.MethodType,types.BuiltinFunctionType,
                    types.BuiltinMethodType,types.ModuleType,types.FileType,types.XRangeType,
                    types.TracebackType,types.FrameType,types.EllipsisType,types.DictProxyType,
                    types.NotImplementedType,types.GetSetDescriptorType,types.MemberDescriptorType
                    ))

    def instantiated(v):
        return not isinstance(v,type) and hasattr(v,'__class__')

    int2Byte = chr

    from StringIO import StringIO
    def getBytesIO(buf=None):
        '''unified StringIO instance interface'''
        if buf:
            return StringIO(buf)
        return StringIO()
    getStringIO = getBytesIO
    _bytesIOType = StringIO 

    def bytestr(x,enc='utf8'):
        if isinstance(x,unicode):
            return x.encode(enc)
        elif isinstance(x,str):
            return x
        else:
            return str(x).encode(enc)
    from string import letters as ascii_letters, uppercase as ascii_uppercase, lowercase as ascii_lowercase

    def encode_label(args):
        return base64_encodebytes(pickle.dumps(args)).strip()

    def decode_label(label):
        return pickle.loads(base64_decodebytes(label))

    def rawUnicode(s):
        '''converts first 256 unicodes 1-1'''
        return s.decode('latin1') if not isinstance(s,unicode) else s

    def rawBytes(s):
        '''converts first 256 unicodes 1-1'''
        return s.encode('latin1') if isinstance(s,unicode) else s

    def rl_exec(obj, G=None, L=None):
        '''this is unsafe'''
        if G is None:
            frame = sys._getframe(1)
            G = frame.f_globals
            if L is None:
                L = frame.f_locals
            del frame
        elif L is None:
            L = G
        exec(obj,G, L)
    rl_exec("""def rl_reraise(t, v, b=None):\n\traise t, v, b\n""")

    char2int = ord
    def rl_add_builtins(**kwd):
        import __builtin__
        for k,v in kwd.items():
            setattr(__builtin__,k,v)

def zipImported(ldr=None):
    try:
        if not ldr:
            ldr = sys._getframe(1).f_globals['__loader__']
        from zipimport import zipimporter
        return ldr if isinstance(ldr,zipimporter) and len(ldr._files) else None
    except:
        return None

def _findFiles(dirList,ext='.ttf'):
    from os.path import isfile, isdir, join as path_join
    from os import listdir
    ext = ext.lower()
    R = []
    A = R.append
    for D in dirList:
        if not isdir(D): continue
        for fn in listdir(D):
            fn = path_join(D,fn)
            if isfile(fn) and (not ext or fn.lower().endswith(ext)): A(fn)
    return R

class CIDict(dict):
    def __init__(self,*args,**kwds):
        for a in args: self.update(a)
        self.update(kwds)

    def update(self,D):
        for k,v in D.items(): self[k] = v

    def __setitem__(self,k,v):
        try:
            k = k.lower()
        except:
            pass
        dict.__setitem__(self,k,v)

    def __getitem__(self,k):
        try:
            k = k.lower()
        except:
            pass
        return dict.__getitem__(self,k)

    def __delitem__(self,k):
        try:
            k = k.lower()
        except:
            pass
        return dict.__delitem__(self,k)

    def get(self,k,dv=None):
        try:
            return self[k]
        except KeyError:
            return dv

    def __contains__(self,k):
        try:
            self[k]
            return True
        except:
            return False

    def pop(self,k,*a):
        try:
            k = k.lower()
        except:
            pass
        return dict.pop(*((self,k)+a))

    def setdefault(self,k,*a):
        try:
            k = k.lower()
        except:
            pass
        return dict.setdefault(*((self,k)+a))

if os.name == 'mac':
    #with the Mac, we need to tag the file in a special
    #way so the system knows it is a PDF file.
    #This supplied by Joe Strout
    import macfs, macostools
    _KNOWN_MAC_EXT = {
        'BMP' : ('ogle','BMP '),
        'EPS' : ('ogle','EPSF'),
        'EPSF': ('ogle','EPSF'),
        'GIF' : ('ogle','GIFf'),
        'JPG' : ('ogle','JPEG'),
        'JPEG': ('ogle','JPEG'),
        'PCT' : ('ttxt','PICT'),
        'PICT': ('ttxt','PICT'),
        'PNG' : ('ogle','PNGf'),
        'PPM' : ('ogle','.PPM'),
        'TIF' : ('ogle','TIFF'),
        'TIFF': ('ogle','TIFF'),
        'PDF' : ('CARO','PDF '),
        'HTML': ('MSIE','TEXT'),
        }
    def markfilename(filename,creatorcode=None,filetype=None,ext='PDF'):
        try:
            if creatorcode is None or filetype is None and ext is not None:
                try:
                    creatorcode, filetype = _KNOWN_MAC_EXT[ext.upper()]
                except:
                    return
            macfs.FSSpec(filename).SetCreatorType(creatorcode,filetype)
            macostools.touched(filename)
        except:
            pass
else:
    def markfilename(filename,creatorcode=None,filetype=None):
        pass

import reportlab
__RL_DIR=os.path.dirname(reportlab.__file__)    #possibly relative
_RL_DIR=os.path.isabs(__RL_DIR) and __RL_DIR or os.path.abspath(__RL_DIR)
del reportlab

#Attempt to detect if this copy of reportlab is running in a
#file system (as opposed to mostly running in a zip or McMillan
#archive or Jar file).  This is used by test cases, so that
#we can write test cases that don't get activated in frozen form.
try:
    __file__
except:
    __file__ = sys.argv[0]
import glob, fnmatch
try:
    __rl_loader__ = __loader__
    _isFSD = not __rl_loader__
    if not zipImported(ldr=__rl_loader__):
        raise NotImplementedError("can't handle compact distro type %r" % __rl_loader__)
    _archive = os.path.normcase(os.path.normpath(__rl_loader__.archive))
    _archivepfx = _archive + os.sep
    _archivedir = os.path.dirname(_archive)
    _archivedirpfx = _archivedir + os.sep
    _archivepfxlen = len(_archivepfx)
    _archivedirpfxlen = len(_archivedirpfx)
    def __startswith_rl(fn,
                    _archivepfx=_archivepfx,
                    _archivedirpfx=_archivedirpfx,
                    _archive=_archive,
                    _archivedir=_archivedir,
                    os_path_normpath=os.path.normpath,
                    os_path_normcase=os.path.normcase,
                    os_getcwd=os.getcwd,
                    os_sep=os.sep,
                    os_sep_len = len(os.sep)):
        '''if the name starts with a known prefix strip it off'''
        fn = os_path_normpath(fn.replace('/',os_sep))
        nfn = os_path_normcase(fn)
        if nfn in (_archivedir,_archive): return 1,''
        if nfn.startswith(_archivepfx): return 1,fn[_archivepfxlen:]
        if nfn.startswith(_archivedirpfx): return 1,fn[_archivedirpfxlen:]
        cwd = os_path_normcase(os_getcwd())
        n = len(cwd)
        if nfn.startswith(cwd):
            if fn[n:].startswith(os_sep): return 1, fn[n+os_sep_len:]
            if n==len(fn): return 1,''
        return not os.path.isabs(fn),fn

    def _startswith_rl(fn):
        return __startswith_rl(fn)[1]

    def rl_glob(pattern,glob=glob.glob,fnmatch=fnmatch.fnmatch, _RL_DIR=_RL_DIR,pjoin=os.path.join):
        c, pfn = __startswith_rl(pattern)
        r = glob(pfn)
        if c or r==[]:
            r += list(map(lambda x,D=_archivepfx,pjoin=pjoin: pjoin(_archivepfx,x),list(filter(lambda x,pfn=pfn,fnmatch=fnmatch: fnmatch(x,pfn),list(__rl_loader__._files.keys())))))
        return r
except:
    _isFSD = os.path.isfile(__file__)   #slight risk of wrong path
    __rl_loader__ = None
    def _startswith_rl(fn):
        return fn
    def rl_glob(pattern,glob=glob.glob):
        return glob(pattern)
del glob, fnmatch
_isFSSD = _isFSD and os.path.isfile(os.path.splitext(__file__)[0] +'.py')

def isFileSystemDistro():
    '''return truth if a file system distribution'''
    return _isFSD

def isCompactDistro():
    '''return truth if not a file system distribution'''
    return not _isFSD

def isSourceDistro():
    '''return truth if a source file system distribution'''
    return _isFSSD

def recursiveImport(modulename, baseDir=None, noCWD=0, debug=0):
    """Dynamically imports possible packagized module, or raises ImportError"""
    normalize = lambda x: os.path.normcase(os.path.abspath(os.path.normpath(x)))
    path = [normalize(p) for p in sys.path]
    if baseDir:
        if not isSeq(baseDir):
            tp = [baseDir]
        else:
            tp = filter(None,list(baseDir))
        for p in tp:
            p = normalize(p)
            if p not in path: path.insert(0,p)

    if noCWD:
        for p in ('','.',normalize('.')):
            while p in path:
                if debug: print('removed "%s" from path' % p)
                path.remove(p)
    elif '.' not in path:
            path.insert(0,'.')

    if debug:
        import pprint
        pp = pprint.pprint
        print('path=')
        pp(path)

    #make import errors a bit more informative
    opath = sys.path
    try:
        try:
            sys.path = path
            NS = {}
            rl_exec('import %s as m' % modulename,NS)
            return NS['m']
        except ImportError:
            sys.path = opath
            msg = "Could not import '%s'" % modulename
            if baseDir:
                msg = msg + " under %s" % baseDir
            annotateException(msg)
        except:
            e = sys.exc_info()
            msg = "Exception raised while importing '%s': %s" % (modulename, e[1])
            annotateException(msg)
    finally:
        sys.path = opath

def import_zlib():
    try:
        import zlib
    except ImportError:
        zlib = None
        from reportlab.rl_config import ZLIB_WARNINGS
        if ZLIB_WARNINGS: warnOnce('zlib not available')
    return zlib

# Image Capability Detection.  Set a flag haveImages
# to tell us if either PIL or Java imaging libraries present.
# define PIL_Image as either None, or an alias for the PIL.Image
# module, as there are 2 ways to import it
if sys.platform[0:4] == 'java':
    try:
        import javax.imageio
        import java.awt.image
        haveImages = 1
    except:
        haveImages = 0
else:
    try:
        from PIL import Image
    except ImportError:
        try:
            import Image
        except ImportError:
            Image = None
    haveImages = Image is not None

class ArgvDictValue:
    '''A type to allow clients of getArgvDict to specify a conversion function'''
    def __init__(self,value,func):
        self.value = value
        self.func = func

def getArgvDict(**kw):
    ''' Builds a dictionary from its keyword arguments with overrides from sys.argv.
        Attempts to be smart about conversions, but the value can be an instance
        of ArgDictValue to allow specifying a conversion function.
    '''
    def handleValue(v,av,func):
        if func:
            v = func(av)
        else:
            if isStr(v):
                v = av
            elif isinstance(v,float):
                v = float(av)
            elif isinstance(v,int):
                v = int(av)
            elif isinstance(v,list):
                v = list(literal_eval(av),{})
            elif isinstance(v,tuple):
                v = tuple(literal_eval(av),{})
            else:
                raise TypeError("Can't convert string %r to %s" % (av,type(v)))
        return v

    A = sys.argv[1:]
    R = {}
    for k, v in kw.items():
        if isinstance(v,ArgvDictValue):
            v, func = v.value, v.func
        else:
            func = None
        handled = 0
        ke = k+'='
        for a in A:
            if a.startswith(ke):
                av = a[len(ke):]
                A.remove(a)
                R[k] = handleValue(v,av,func)
                handled = 1
                break

        if not handled: R[k] = handleValue(v,v,func)

    return R

def getHyphenater(hDict=None):
    try:
        from reportlab.lib.pyHnj import Hyphen
        if hDict is None: hDict=os.path.join(os.path.dirname(__file__),'hyphen.mashed')
        return Hyphen(hDict)
    except ImportError as errMsg:
        if str(errMsg)!='No module named pyHnj': raise
        return None

def _className(self):
    '''Return a shortened class name'''
    try:
        name = self.__class__.__name__
        i=name.rfind('.')
        if i>=0: return name[i+1:]
        return name
    except AttributeError:
        return str(self)

def open_for_read_by_name(name,mode='b'):
    if 'r' not in mode: mode = 'r'+mode
    try:
        return open(name,mode)
    except IOError:
        if _isFSD or __rl_loader__ is None: raise
        #we have a __rl_loader__, perhaps the filename starts with
        #the dirname(reportlab.__file__) or is relative
        name = _startswith_rl(name)
        s = __rl_loader__.get_data(name)
        if 'b' not in mode and os.linesep!='\n': s = s.replace(os.linesep,'\n')
        return getBytesIO(s)

def open_for_read(name,mode='b'):
    #auto initialized function`
    if not isPy3:
        import urllib2, urllib
        from urlparse import urlparse
        urlopen=urllib2.urlopen
        def datareader(url,opener=urllib.URLopener().open):
            return opener(url).read()
        del urllib, urllib2
    else:
        from urllib.request import urlopen
        from urllib.parse import unquote, urlparse
        #copied here from urllib.URLopener.open_data because
        # 1) they want to remove it
        # 2) the existing one is borken
        def datareader(url, unquote=unquote):
            """Use "data" URL."""
            # ignore POSTed data
            #
            # syntax of data URLs:
            # dataurl   := "data:" [ mediatype ] [ ";base64" ] "," data
            # mediatype := [ type "/" subtype ] *( ";" parameter )
            # data      := *urlchar
            # parameter := attribute "=" value
            try:
                typ, data = url.split(',', 1)
            except ValueError:
                raise IOError('data error', 'bad data URL')
            if not typ:
                typ = 'text/plain;charset=US-ASCII'
            semi = typ.rfind(';')
            if semi >= 0 and '=' not in typ[semi:]:
                encoding = typ[semi+1:]
                typ = typ[:semi]
            else:
                encoding = ''
            if encoding == 'base64':
                # XXX is this encoding/decoding ok?
                data = base64_decodebytes(data.encode('ascii'))
            else:
                data = unquote(data).encode('latin-1')
            return data
    from reportlab.rl_config import trustedHosts, trustedSchemes
    if trustedHosts:
        import re, fnmatch
        def xre(s):
            s = fnmatch.translate(s)
            return s[4:-3] if s.startswith('(?s:') else s[:-7]
        trustedHosts = re.compile(''.join(('^(?:',
                                '|'.join(map(xre,trustedHosts)),
                                ')\\Z')))
    def open_for_read(name,mode='b'):
        '''attempt to open a file or URL for reading'''
        if hasattr(name,'read'): return name
        try:
            return open_for_read_by_name(name,mode)
        except:
            try:
                if trustedHosts is not None:
                    purl = urlparse(name)
                    if purl[0] and not ((purl[0] in ('data','file') or trustedHosts.match(purl[1])) and (purl[0] in trustedSchemes)):
                        raise ValueError('Attempted untrusted host access')
                return getBytesIO(datareader(name) if name[:5].lower()=='data:' else urlopen(name).read())
            except:
                raise IOError('Cannot open resource "%s"' % name)
    globals()['open_for_read'] = open_for_read
    return open_for_read(name,mode)

def open_and_read(name,mode='b'):
    f = open_for_read(name,mode)
    if name is not f and hasattr(f,'__exit__'):
        with f:
            return f.read()
    else:
        return f.read()

def open_and_readlines(name,mode='t'):
    return open_and_read(name,mode).split('\n')

def rl_isfile(fn,os_path_isfile=os.path.isfile):
    if hasattr(fn,'read'): return True
    if os_path_isfile(fn): return True
    if _isFSD or __rl_loader__ is None: return False
    fn = _startswith_rl(fn)
    return fn in list(__rl_loader__._files.keys())

def rl_isdir(pn,os_path_isdir=os.path.isdir,os_path_normpath=os.path.normpath):
    if os_path_isdir(pn): return True
    if _isFSD or __rl_loader__ is None: return False
    pn = _startswith_rl(os_path_normpath(pn))
    if not pn.endswith(os.sep): pn += os.sep
    return len(list(filter(lambda x,pn=pn: x.startswith(pn),list(__rl_loader__._files.keys()))))>0

def rl_listdir(pn,os_path_isdir=os.path.isdir,os_path_normpath=os.path.normpath,os_listdir=os.listdir):
    if os_path_isdir(pn) or _isFSD or __rl_loader__ is None: return os_listdir(pn)
    pn = _startswith_rl(os_path_normpath(pn))
    if not pn.endswith(os.sep): pn += os.sep
    return [x[len(pn):] for x in __rl_loader__._files.keys() if x.startswith(pn)]

def rl_getmtime(pn,os_path_isfile=os.path.isfile,os_path_normpath=os.path.normpath,os_path_getmtime=os.path.getmtime,time_mktime=time.mktime):
    if os_path_isfile(pn) or _isFSD or __rl_loader__ is None: return os_path_getmtime(pn)
    p = _startswith_rl(os_path_normpath(pn))
    try:
        e = __rl_loader__._files[p]
    except KeyError:
        return os_path_getmtime(pn)
    s = e[5]
    d = e[6]
    return time_mktime((((d>>9)&0x7f)+1980,(d>>5)&0xf,d&0x1f,(s>>11)&0x1f,(s>>5)&0x3f,(s&0x1f)<<1,0,0,0))

if isPy3 and sys.version_info[:2]>=(3,4):
    from importlib import util as importlib_util
    def __rl_get_module__(name,dir):
        for ext in ('.py','.pyw','.pyo','.pyc','.pyd'):
            path = os.path.join(dir,name+ext)
            if os.path.isfile(path):
                spec = importlib_util.spec_from_file_location(name,path)
                return spec.loader.load_module()
        raise ImportError('no suitable file found')
else:
    import imp
    def __rl_get_module__(name,dir):
        f, p, desc= imp.find_module(name,[dir])
        try:
            return imp.load_module(name,f,p,desc)
        finally:
            if f:
                f.close()

def rl_get_module(name,dir):
    if name in sys.modules:
        om = sys.modules[name]
        del sys.modules[name]
    else:
        om = None
    try:
        try:
            return __rl_get_module__(name,dir)
        except:
            if isCompactDistro():
                #attempt a load from inside the zip archive
                import zipimport
                dir = _startswith_rl(dir)
                dir = (dir=='.' or not dir) and _archive or os.path.join(_archive,dir.replace('/',os.sep))
                zi = zipimport.zipimporter(dir)
                return zi.load_module(name)
            raise ImportError('%s[%s]' % (name,dir))
    finally:
        if om: sys.modules[name] = om

def _isPILImage(im):
    try:
        return isinstance(im,Image.Image)
    except AttributeError:
        return 0

class ImageReader(object):
    "Wraps up either PIL or Java to get data from bitmaps"
    _cache={}
    _max_image_size = None
    def __init__(self, fileName,ident=None):
        if isinstance(fileName,ImageReader):
            self.__dict__ = fileName.__dict__   #borgize
            return
        self._ident = ident
        #start wih lots of null private fields, to be populated by
        #the relevant engine.
        self.fileName = fileName
        self._image = None
        self._width = None
        self._height = None
        self._transparent = None
        self._data = None
        if _isPILImage(fileName):
            self._image = fileName
            self.fp = getattr(fileName,'fp',None)
            try:
                self.fileName = self._image.fileName
            except AttributeError:
                self.fileName = 'PILIMAGE_%d' % id(self)
        else:
            try:
                from reportlab.rl_config import imageReaderFlags
                self.fp = open_for_read(fileName,'b')
                if isinstance(self.fp,_bytesIOType): imageReaderFlags=0 #avoid messing with already internal files
                if imageReaderFlags>0:  #interning
                    data = self.fp.read()
                    if imageReaderFlags&2:  #autoclose
                        try:
                            self.fp.close()
                        except:
                            pass
                    if imageReaderFlags&4:  #cache the data
                        if not self._cache:
                            from rl_config import register_reset
                            register_reset(self._cache.clear)
                        data=self._cache.setdefault(_digester(data),data)
                    self.fp=getBytesIO(data)
                elif imageReaderFlags==-1 and isinstance(fileName,str):
                    #try Ralf Schmitt's re-opening technique of avoiding too many open files
                    self.fp.close()
                    del self.fp #will become a property in the next statement
                    self.__class__=LazyImageReader
                if haveImages:
                    #detect which library we are using and open the image
                    if not self._image:
                        self._image = self._read_image(self.fp)
                        self.check_pil_image_size(self._image)
                    if getattr(self._image,'format',None)=='JPEG': self.jpeg_fh = self._jpeg_fh
                else:
                    from reportlab.pdfbase.pdfutils import readJPEGInfo
                    try:
                        self._width,self._height,c=readJPEGInfo(self.fp)
                    except:
                        annotateException('\nImaging Library not available, unable to import bitmaps only jpegs\nfileName=%r identity=%s'%(fileName,self.identity()))
                    size = self._width*self._height*c
                    if self._max_image_size is not None and size>self._max+image_size:
                        raise MemoryError('JPEG %s color %s x %s image would use %s > %s bytes'
                                            %(c,self._width,self._height,size,self._max_image_size))
                    self.jpeg_fh = self._jpeg_fh
                    self._data = self.fp.read()
                    self._dataA=None
                    self.fp.seek(0)
            except:
                annotateException('\nfileName=%r identity=%s'%(fileName,self.identity()))

    def identity(self):
        '''try to return information that will identify the instance'''
        fn = self.fileName
        if not isStr(fn):
            fn = getattr(getattr(self,'fp',None),'name',None)
        ident = self._ident
        return '[%s@%s%s%s]' % (self.__class__.__name__,hex(id(self)),ident and (' ident=%r' % ident) or '',fn and (' filename=%r' % fn) or '')

    def _read_image(self,fp):
        if sys.platform[0:4] == 'java':
            from javax.imageio import ImageIO
            return ImageIO.read(fp)
        else:
            return Image.open(fp)

    @classmethod
    def check_pil_image_size(cls, im):
        max_image_size = cls._max_image_size
        if max_image_size is None: return
        w, h = im.size
        m = im.mode
        size = max(1,((1 if m=='1' else 8*len(m))*w*h)>>3)
        if size>max_image_size:
            raise MemoryError('PIL %s %s x %s image would use %s > %s bytes'
                                            %(m,w,h,size,max_image_size))
    @classmethod
    def set_max_image_size(cls,max_image_size=None):
        cls._max_image_size = max_image_size
        if max_image_size is not None:
            from reportlab.rl_config import register_reset
            register_reset(cls.set_max_image_size)

    def _jpeg_fh(self):
        fp = self.fp
        fp.seek(0)
        return fp

    def jpeg_fh(self):
        return None

    def getSize(self):
        if (self._width is None or self._height is None):
            if sys.platform[0:4] == 'java':
                self._width = self._image.getWidth()
                self._height = self._image.getHeight()
            else:
                self._width, self._height = self._image.size
        return (self._width, self._height)

    def getRGBData(self):
        "Return byte array of RGB data as string"
        try:
            if self._data is None:
                self._dataA = None
                if sys.platform[0:4] == 'java':
                    import jarray
                    from java.awt.image import PixelGrabber
                    width, height = self.getSize()
                    buffer = jarray.zeros(width*height, 'i')
                    pg = PixelGrabber(self._image, 0,0,width,height,buffer,0,width)
                    pg.grabPixels()
                    # there must be a way to do this with a cast not a byte-level loop,
                    # I just haven't found it yet...
                    pixels = []
                    a = pixels.append
                    for i in range(len(buffer)):
                        rgb = buffer[i]
                        a(chr((rgb>>16)&0xff))
                        a(chr((rgb>>8)&0xff))
                        a(chr(rgb&0xff))
                    self._data = ''.join(pixels)
                    self.mode = 'RGB'
                else:
                    im = self._image
                    mode = self.mode = im.mode
                    if mode in ('LA','RGBA'):
                        if getattr(Image,'VERSION','').startswith('1.1.7'): im.load()
                        self._dataA = ImageReader(im.split()[3 if mode=='RGBA' else 1])
                        nm = mode[:-1]
                        im = im.convert(nm)
                        self.mode = nm
                    elif mode not in ('L','RGB','CMYK'):
                        if im.format=='PNG' and im.mode=='P' and 'transparency' in im.info:
                            im = im.convert('RGBA')
                            self._dataA = ImageReader(im.split()[3])
                            im = im.convert('RGB')
                        else:
                            im = im.convert('RGB')
                        self.mode = 'RGB'
                    self._data = (im.tobytes if hasattr(im, 'tobytes') else im.tostring)()  #make pillow and PIL both happy, for now
            return self._data
        except:
            annotateException('\nidentity=%s'%self.identity())

    def getImageData(self):
        width, height = self.getSize()
        return width, height, self.getRGBData()

    def getTransparent(self):
        if sys.platform[0:4] == 'java':
            return None
        else:
            if "transparency" in self._image.info:
                transparency = self._image.info["transparency"] * 3
                palette = self._image.palette
                try:
                    palette = palette.palette
                except:
                    try:
                        palette = palette.data
                    except:
                        return None
                if isPy3:
                    return palette[transparency:transparency+3]
                else:
                    return [ord(c) for c in palette[transparency:transparency+3]]
            else:
                return None

class LazyImageReader(ImageReader): 
    def fp(self): 
        return open_for_read(self.fileName, 'b') 
    fp=property(fp) 

    def _image(self):
        return self._read_image(self.fp)
    _image=property(_image) 

def getImageData(imageFileName):
    "Get width, height and RGB pixels from image file.  Wraps Java/PIL"
    try:
        return imageFileName.getImageData()
    except AttributeError:
        return ImageReader(imageFileName).getImageData()

class DebugMemo:
    '''Intended as a simple report back encapsulator

    Typical usages:
        
    1. To record error data::
        
        dbg = DebugMemo(fn='dbgmemo.dbg',myVar=value)
        dbg.add(anotherPayload='aaaa',andagain='bbb')
        dbg.dump()

    2. To show the recorded info::
        
        dbg = DebugMemo(fn='dbgmemo.dbg',mode='r')
        dbg.load()
        dbg.show()

    3. To re-use recorded information::
        
        dbg = DebugMemo(fn='dbgmemo.dbg',mode='r')
            dbg.load()
        myTestFunc(dbg.payload('myVar'),dbg.payload('andagain'))

    In addition to the payload variables the dump records many useful bits
    of information which are also printed in the show() method.
    '''
    def __init__(self,fn='rl_dbgmemo.dbg',mode='w',getScript=1,modules=(),capture_traceback=1, stdout=None, **kw):
        import time, socket
        self.fn = fn
        if not stdout: 
            self.stdout = sys.stdout
        else:
            if hasattr(stdout,'write'):
                self.stdout = stdout
            else:
                self.stdout = open(stdout,'w')
        if mode!='w': return
        self.store = store = {}
        if capture_traceback and sys.exc_info() != (None,None,None):
            import traceback
            s = getBytesIO()
            traceback.print_exc(None,s)
            store['__traceback'] = s.getvalue()
        cwd=os.getcwd()
        lcwd = os.listdir(cwd)
        pcwd = os.path.dirname(cwd)
        lpcwd = pcwd and os.listdir(pcwd) or '???'
        exed = os.path.abspath(os.path.dirname(sys.argv[0]))
        project_version='???'
        md=None
        try:
            import marshal
            md=marshal.loads(__rl_loader__.get_data('meta_data.mar'))
            project_version=md['project_version']
        except:
            pass
        env = os.environ
        K=list(env.keys())
        K.sort()
        store.update({  'gmt': time.asctime(time.gmtime(time.time())),
                        'platform': sys.platform,
                        'version': sys.version,
                        'hexversion': hex(sys.hexversion),
                        'executable': sys.executable,
                        'exec_prefix': sys.exec_prefix,
                        'prefix': sys.prefix,
                        'path': sys.path,
                        'argv': sys.argv,
                        'cwd': cwd,
                        'hostname': socket.gethostname(),
                        'lcwd': lcwd,
                        'lpcwd': lpcwd,
                        'byteorder': sys.byteorder,
                        'maxint': getattr(sys,'maxunicode','????'),
                        'api_version': getattr(sys,'api_version','????'),
                        'version_info': getattr(sys,'version_info','????'),
                        'winver': getattr(sys,'winver','????'),
                        'environment': '\n\t\t\t'.join(['']+['%s=%r' % (k,env[k]) for k in K]),
                        '__rl_loader__': repr(__rl_loader__),
                        'project_meta_data': md,
                        'project_version': project_version,
                        })
        for M,A in (
                (sys,('getwindowsversion','getfilesystemencoding')),
                (os,('uname', 'ctermid', 'getgid', 'getuid', 'getegid',
                    'geteuid', 'getlogin', 'getgroups', 'getpgrp', 'getpid', 'getppid',
                    )),
                ):
            for a in A:
                if hasattr(M,a):
                    try:
                        store[a] = getattr(M,a)()
                    except:
                        pass
        if exed!=cwd:
            try:
                store.update({'exed': exed, 'lexed': os.listdir(exed),})
            except:
                pass
        if getScript:
            fn = os.path.abspath(sys.argv[0])
            if os.path.isfile(fn):
                try:
                    store['__script'] = (fn,open(fn,'r').read())
                except:
                    pass
        module_versions = {}
        for n,m in sys.modules.items():
            if n=='reportlab' or n=='rlextra' or n[:10]=='reportlab.' or n[:8]=='rlextra.':
                v = [getattr(m,x,None) for x in ('__version__','__path__','__file__')]
                if [_f for _f in v if _f]:
                    v = [v[0]] + [_f for _f in v[1:] if _f]
                    module_versions[n] = tuple(v)
        store['__module_versions'] = module_versions
        self.store['__payload'] = {}
        self._add(kw)

    def _add(self,D):
        payload = self.store['__payload']
        for k, v in D.items():
            payload[k] = v

    def add(self,**kw):
        self._add(kw)

    def _dump(self,f):
        try:
            pos=f.tell()
            pickle.dump(self.store,f)
        except:
            S=self.store.copy()
            ff=getBytesIO()
            for k,v in S.items():
                try:
                    pickle.dump({k:v},ff)
                except:
                    S[k] = '<unpicklable object %r>' % v
            f.seek(pos,0)
            pickle.dump(S,f)

    def dump(self):
        f = open(self.fn,'wb')
        try:
            self._dump(f)
        finally:
            f.close()

    def dumps(self):
        f = getBytesIO()
        self._dump(f)
        return f.getvalue()

    def _load(self,f):
        self.store = pickle.load(f)

    def load(self):
        f = open(self.fn,'rb')
        try:
            self._load(f)
        finally:
            f.close()

    def loads(self,s):
        self._load(getBytesIO(s))

    def _show_module_versions(self,k,v):
        self._writeln(k[2:])
        K = list(v.keys())
        K.sort()
        for k in K:
            vk = vk0 = v[k]
            if isinstance(vk,tuple): vk0 = vk[0]
            try:
                __import__(k)
                m = sys.modules[k]
                d = getattr(m,'__version__',None)==vk0 and 'SAME' or 'DIFFERENT'
            except:
                m = None
                d = '??????unknown??????'
            self._writeln('  %s = %s (%s)' % (k,vk,d))

    def _banner(self,k,what):
        self._writeln('###################%s %s##################' % (what,k[2:]))

    def _start(self,k):
        self._banner(k,'Start  ')

    def _finish(self,k):
        self._banner(k,'Finish ')

    def _show_lines(self,k,v):
        self._start(k)
        self._writeln(v)
        self._finish(k)

    def _show_file(self,k,v):
        k = '%s %s' % (k,os.path.basename(v[0]))
        self._show_lines(k,v[1])

    def _show_payload(self,k,v):
        if v:
            import pprint
            self._start(k)
            pprint.pprint(v,self.stdout)
            self._finish(k)

    def _show_extensions(self):
        for mn in ('_rl_accel','_renderPM','sgmlop','pyRXP','pyRXPU','_imaging','Image'):
            try:
                A = [mn].append
                __import__(mn)
                m = sys.modules[mn]
                A(m.__file__)
                for vn in ('__version__','VERSION','_version','version'):
                    if hasattr(m,vn):
                        A('%s=%r' % (vn,getattr(m,vn)))
            except:
                A('not found')
            self._writeln(' '+' '.join(A.__self__))

    specials = {'__module_versions': _show_module_versions,
                '__payload': _show_payload,
                '__traceback': _show_lines,
                '__script': _show_file,
                }
    def show(self):
        K = list(self.store.keys())
        K.sort()
        for k in K:
            if k not in list(self.specials.keys()): self._writeln('%-15s = %s' % (k,self.store[k]))
        for k in K:
            if k in list(self.specials.keys()): self.specials[k](self,k,self.store[k])
        self._show_extensions()

    def payload(self,name):
        return self.store['__payload'][name]

    def __setitem__(self,name,value):
        self.store['__payload'][name] = value

    def __getitem__(self,name):
        return self.store['__payload'][name]

    def _writeln(self,msg):
        self.stdout.write(msg+'\n')

def _flatten(L,a):
    for x in L:
        if isSeq(x): _flatten(x,a)
        else: a(x)

def flatten(L):
    '''recursively flatten the list or tuple L'''
    R = []
    _flatten(L,R.append)
    return R

def find_locals(func,depth=0):
    '''apply func to the locals at each stack frame till func returns a non false value'''
    while 1:
        _ = func(sys._getframe(depth).f_locals)
        if _: return _
        depth += 1

class _FmtSelfDict:
    def __init__(self,obj,overrideArgs):
        self.obj = obj
        self._overrideArgs = overrideArgs
    def __getitem__(self,k):
        try:
            return self._overrideArgs[k]
        except KeyError:
            try:
                return self.obj.__dict__[k]
            except KeyError:
                return getattr(self.obj,k)

class FmtSelfDict:
    '''mixin to provide the _fmt method'''
    def _fmt(self,fmt,**overrideArgs):
        D = _FmtSelfDict(self, overrideArgs)
        return fmt % D

def _simpleSplit(txt,mW,SW):
    L = []
    ws = SW(' ')
    O = []
    w = -ws
    for t in txt.split():
        lt = SW(t)
        if w+ws+lt<=mW or O==[]:
            O.append(t)
            w = w + ws + lt
        else:
            L.append(' '.join(O))
            O = [t]
            w = lt
    if O!=[]: L.append(' '.join(O))
    return L

def simpleSplit(text,fontName,fontSize,maxWidth):
    from reportlab.pdfbase.pdfmetrics import stringWidth
    lines = asUnicode(text).split(u'\n')
    SW = lambda text, fN=fontName, fS=fontSize: stringWidth(text, fN, fS)
    if maxWidth:
        L = []
        for l in lines:
            L.extend(_simpleSplit(l,maxWidth,SW))
        lines = L
    return lines

def escapeTextOnce(text):
    "Escapes once only"
    from xml.sax.saxutils import escape
    if text is None:
        return text
    if isBytes(text): s = text.decode('utf8')
    text = escape(text)
    text = text.replace(u'&amp;amp;',u'&amp;')
    text = text.replace(u'&amp;gt;', u'&gt;')
    text = text.replace(u'&amp;lt;', u'&lt;')
    return text

if isPy3:
    def fileName2FSEnc(fn):
        if isUnicode(fn):
            return  fn
        else:
            for enc in fsEncodings:
                try:
                    return fn.decode(enc)
                except:
                    pass
        raise ValueError('cannot convert %r to filesystem encoding' % fn)
else:
    def fileName2FSEnc(fn):
        '''attempt to convert a filename to utf8'''
        from reportlab.rl_config import fsEncodings
        if isUnicode(fn):
            return asBytes(fn)
        else:
            for enc in fsEncodings:
                try:
                    return fn.decode(enc).encode('utf8')
                except:
                    pass
        raise ValueError('cannot convert %r to utf8 for file path name' % fn)

import itertools
def prev_this_next(items):
    """
    Loop over a collection with look-ahead and look-back.
    
    From Thomas Guest, 
    http://wordaligned.org/articles/zippy-triples-served-with-python
    
    Seriously useful looping tool (Google "zippy triples")
    lets you loop a collection and see the previous and next items,
    which get set to None at the ends.
    
    To be used in layout algorithms where one wants a peek at the
    next item coming down the pipe.

    """
    
    extend = itertools.chain([None], items, [None])
    prev, this, next = itertools.tee(extend, 3)
    try:
        next(this)
        next(next)
        next(next)
    except StopIteration:
        pass
    return zip(prev, this, next)

def commasplit(s):
    '''
    Splits the string s at every unescaped comma and returns the result as a list.
    To escape a comma, double it. Individual items are stripped.
    To avoid the ambiguity of 3 successive commas to denote a comma at the beginning
    or end of an item, add a space between the item seperator and the escaped comma.
    
    >>> commasplit(u'a,b,c') == [u'a', u'b', u'c']
    True
    >>> commasplit('a,, , b , c    ') == [u'a,', u'b', u'c']
    True
    >>> commasplit(u'a, ,,b, c') == [u'a', u',b', u'c']
    '''
    if isBytes(s): s = s.decode('utf8')
    n = len(s)-1
    s += u' '
    i = 0
    r=[u'']
    while i<=n:
        if s[i]==u',':
            if s[i+1]==u',':
                r[-1]+=u','
                i += 1
            else:
                r[-1] = r[-1].strip()
                if i!=n: r.append(u'')
        else:
            r[-1] += s[i]
        i+=1
    r[-1] = r[-1].strip()
    return r
    
def commajoin(l):
    '''
    Inverse of commasplit, except that whitespace around items is not conserved.
    Adds more whitespace than needed for simplicity and performance.
    
    >>> commasplit(commajoin(['a', 'b', 'c'])) == [u'a', u'b', u'c']
    True
    >>> commasplit((commajoin([u'a,', u' b ', u'c'])) == [u'a,', u'b', u'c']
    True
    >>> commasplit((commajoin([u'a ', u',b', u'c'])) == [u'a', u',b', u'c'] 
    '''
    return u','.join([ u' ' + asUnicode(i).replace(u',', u',,') + u' ' for i in l ])

def findInPaths(fn,paths,isfile=True,fail=False):
    '''search for relative files in likely places'''
    exists = isfile and os.path.isfile or os.path.isdir
    if exists(fn): return fn
    pjoin = os.path.join
    if not os.path.isabs(fn):
        for p in paths:
            pfn = pjoin(p,fn)
            if exists(pfn):
                return pfn
    if fail: raise ValueError('cannot locate %r with paths=%r' % (fn,paths))
    return fn

def annotateException(msg,enc='utf8',postMsg='',sep=' '):
    '''add msg to the args of an existing exception'''
    t,v,b=sys.exc_info()
    rl_reraise(t,t(sep.join((_ for _ in (msg,str(v),postMsg) if _))),b)

def escapeOnce(data):
    """Ensure XML output is escaped just once, irrespective of input

    >>> escapeOnce('A & B')
    'A &amp; B'
    >>> escapeOnce('C &amp; D')
    'C &amp; D'
    >>> escapeOnce('E &amp;amp; F')
    'E &amp; F'

    """
    data = data.replace("&", "&amp;")

    #...but if it was already escaped, make sure it
    # is not done twice....this will turn any tags
    # back to how they were at the start.
    data = data.replace("&amp;amp;", "&amp;")
    data = data.replace("&amp;gt;", "&gt;")
    data = data.replace("&amp;lt;", "&lt;")
    data = data.replace("&amp;#", "&#")

    #..and just in case someone had double-escaped it, do it again
    data = data.replace("&amp;amp;", "&amp;")
    data = data.replace("&amp;gt;", "&gt;")
    data = data.replace("&amp;lt;", "&lt;")
    return data
    
class IdentStr(str):
    '''useful for identifying things that get split'''
    def __new__(cls,value):
        if isinstance(value,IdentStr):
            inc = value.__inc
            value = value[:-(2+len(str(inc)))]
            inc += 1
        else:
            inc = 0
        value += '[%d]' % inc
        self = str.__new__(cls,value)
        self.__inc = inc
        return self

class RLString(str):
    '''allows specification of extra properties of a string using a dictionary of extra attributes
    eg fontName = RLString('proxima-nova-bold',
                    svgAttrs=dict(family='"proxima-nova"',weight='bold'))
    '''
    def __new__(cls,v,**kwds):
        self = str.__new__(cls,v)
        for k,v in kwds.items():
            setattr(self,k,v)
        return self

def makeFileName(s):
    '''force filename strings to unicode so python can handle encoding stuff'''
    if not isUnicode(s):
        s = s.decode('utf8')
    return s

class FixedOffsetTZ(datetime.tzinfo):
    """Fixed offset in minutes east from UTC."""

    def __init__(self, h, m, name):
        self.__offset = datetime.timedelta(hours=h, minutes = m)
        self.__name = name

    def utcoffset(self, dt):
        return self.__offset

    def tzname(self, dt):
        return self.__name

    def dst(self, dt):
        return datetime.timedelta(0)

class TimeStamp(object):
    def __init__(self,invariant=None):
        if invariant is None:
            from reportlab.rl_config import invariant
        t = os.environ.get('SOURCE_DATE_EPOCH','').strip()
        if invariant or t:
            t = int(t) if t else 946684800.0
            lt = time.gmtime(t)
            dhh = dmm = 0
            self.tzname = 'UTC'
        else:
            t = time.time()
            lt = tuple(time.localtime(t))
            dhh = int(time.timezone / (3600.0))
            dmm = (time.timezone % 3600) % 60
            self.tzname = '' 
        self.t = t
        self.lt = lt
        self.YMDhms = tuple(lt)[:6]
        self.dhh = dhh
        self.dmm = dmm

    @property
    def datetime(self):
        if self.tzname:
            return datetime.datetime.fromtimestamp(self.t,FixedOffsetTZ(self.dhh,self.dmm,self.tzname))
        else:
            return datetime.datetime.now()

    @property
    def asctime(self):
        a = time.asctime(self.lt)
        if not isPy3:
            a = a.split()
            a[2] = a[2].lstrip('0')
            a = ' '.join(a)
        return a

def recursiveGetAttr(obj, name, g=None):
    "Can call down into e.g. object1.object2[4].attr"
    if not isStr(name): raise TypeError('invalid reursive acess using %r' % name)
    name = asNative(name)
    name = name.strip()
    if not name: raise ValueError('empty recursive access')
    dot = '.' if name and name[0] not in '[.(' else ''
    return rl_safe_eval('obj%s%s'%(dot,name), g={}, l=dict(obj=obj))

def recursiveSetAttr(obj, name, value):
    "Can call down into e.g. object1.object2[4].attr = value"
    #get the thing above last.
    tokens = name.split('.')
    if len(tokens) == 1:
        setattr(obj, name, value)
    else:
        most = '.'.join(tokens[:-1])
        last = tokens[-1]
        parent = recursiveGetAttr(obj, most)
        setattr(parent, last, value)

def recursiveDelAttr(obj, name):
    tokens = name.split('.')
    if len(tokens) == 1:
        delattr(obj, name)
    else:
        most = '.'.join(tokens[:-1])
        last = tokens[-1]
        parent = recursiveGetAttr(obj, most)
        delattr(parent, last)

def yieldNoneSplits(L):
    '''yield sublists of L separated by None; the Nones disappear'''
    i = 0
    n = len(L)
    while i<n:
        try:
            j = L.index(None,i)
            yield L[i:j]
            i = j+1
            if not L: break
        except ValueError:
            yield L[i:]
            break
