1 | # This program is public domain |
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2 | """ |
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3 | File extension registry. |
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4 | |
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5 | This provides routines for opening files based on extension, |
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6 | and registers the built-in file extensions. |
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7 | """ |
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8 | import imp,os,sys |
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9 | import logging |
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10 | import os.path |
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11 | def _findReaders(dir): |
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12 | # List of plugin objects |
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13 | plugins = [] |
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14 | # Go through files in plug-in directory |
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15 | try: |
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16 | |
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17 | list = os.listdir(dir) |
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18 | for item in list: |
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19 | |
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20 | toks = os.path.splitext(os.path.basename(item)) |
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21 | if toks[1]=='.py' and not toks[0]=='__init__': |
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22 | name = toks[0] |
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23 | path = [os.path.abspath(dir)] |
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24 | file = None |
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25 | |
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26 | try: |
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27 | print"name",name |
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28 | print "path",path |
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29 | print imp.find_module(name, path) |
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30 | (file, path, info) = imp.find_module(name, path) |
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31 | print"file",file |
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32 | print "path", path |
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33 | print "info",info |
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34 | print"hasattr",imp.load_module( name, file, item, info ) |
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35 | module = imp.load_module( name, file, item, info ) |
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36 | print"module", module |
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37 | |
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38 | if hasattr(module, "Reader"): |
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39 | print "went here" |
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40 | try: |
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41 | plugins.append(module.Reader()) |
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42 | except: |
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43 | log("Error accessing Reader in %s\n %s" % (name, sys.exc_value)) |
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44 | except : |
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45 | print"Error importing %s\n %s" % (name,sys.exc_value) |
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46 | log("Error importing %s\n %s" % (name, sys.exc_value)) |
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47 | finally: |
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48 | if not file==None: |
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49 | file.close() |
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50 | except: |
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51 | # Should raise and catch at a higher level and display error on status bar |
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52 | pass |
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53 | return plugins |
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54 | class Loader(object): |
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55 | """ |
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56 | Associate a file loader with an extension. |
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57 | |
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58 | Note that there may be multiple readers for the same extension. |
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59 | |
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60 | Example: |
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61 | |
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62 | registry = Loader() |
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63 | |
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64 | # Add an association by setting an element |
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65 | registry['.zip'] = unzip |
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66 | |
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67 | # Multiple extensions for one loader |
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68 | registry['.tgz'] = untar |
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69 | registry['.tar.gz'] = untar |
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70 | |
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71 | # Multiple readers for one extension |
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72 | registry['.cx'] = cx1 |
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73 | registry['.cx'] = cx2 |
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74 | registry['.cx'] = cx3 |
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75 | |
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76 | # Can also register a format name for explicit control from caller |
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77 | registry['cx3'] = cx3 |
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78 | |
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79 | # Retrieve readers for a file name |
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80 | registry.lookup('hello.cx') -> [cx3,cx2,cx1] |
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81 | |
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82 | # Run loader on a filename |
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83 | registry.load('hello.cx') -> |
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84 | try: |
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85 | return cx3('hello.cx') |
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86 | except: |
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87 | try: |
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88 | return cx2('hello.cx') |
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89 | except: |
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90 | return cx1('hello.cx') |
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91 | |
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92 | # Load in a specific format ignoring extension |
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93 | registry.load('hello.cx',format='cx3') -> |
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94 | return cx3('hello.cx') |
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95 | """ |
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96 | def __init__(self): |
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97 | self.readers = {} |
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98 | self.reading=None |
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99 | |
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100 | |
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101 | def __setitem__(self, ext=None, reader=None): |
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102 | if reader==None: |
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103 | print os.getcwd() |
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104 | print os.path.isdir('plugins') |
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105 | print "absolute path : ",os.path.abspath('plugins') |
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106 | plugReader=None |
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107 | if os.path.isdir('plugins'): |
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108 | print "went here" |
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109 | plugReader=_findReaders('plugins')# import all module in plugins |
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110 | elif os.path.isdir('../plugins'): |
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111 | plugReader=_findReaders('../plugins') |
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112 | if plugReader !=None: |
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113 | print "this is plugreader",plugReader |
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114 | for preader in plugReader:# for each modules takes list of extensions |
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115 | #print preader.ext |
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116 | for item in preader.ext: |
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117 | ext=item |
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118 | if ext not in self.readers:#assign extension with its reader |
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119 | self.readers[ext] = [] |
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120 | self.readers[ext].insert(0,preader) |
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121 | print "extension",ext |
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122 | print "readers",self.readers |
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123 | else: |
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124 | if ext not in self.readers: |
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125 | self.readers[ext] = [] |
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126 | self.readers[ext].insert(0,reader) |
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127 | |
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128 | |
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129 | def __getitem__(self, ext): |
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130 | return self.readers[ext] |
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131 | |
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132 | |
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133 | |
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134 | def __contains__(self, ext): |
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135 | return ext in self.readers |
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136 | |
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137 | |
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138 | def formats(self, name=True, ext=False): |
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139 | """ |
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140 | Return a list of the registered formats. If name=True then |
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141 | named formats are returned. If ext=True then extensions |
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142 | are returned. |
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143 | """ |
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144 | names = [a for a in self.readers.keys() if not a.startswith('.')] |
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145 | exts = [a for a in self.readers.keys() if a.startswith('.')] |
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146 | names.sort() |
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147 | exts.sort() |
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148 | ret = [] |
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149 | if name: ret += names |
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150 | if ext: ret += exts |
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151 | return ret |
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152 | |
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153 | def lookup(self, path): |
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154 | """ |
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155 | Return the loader associated with the file type of path. |
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156 | """ |
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157 | file = os.path.basename(path) |
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158 | idx = file.find('.') |
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159 | ext = file[idx:] if idx >= 0 else '' |
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160 | try: |
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161 | return self.readers[ext] |
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162 | except: |
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163 | #raise ValueError, "Unknown file type '%s'"%ext |
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164 | print "Unknown file type '%s'"%ext |
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165 | |
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166 | |
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167 | def getAcTReader(self,path): |
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168 | return self.reading |
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169 | |
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170 | def load(self, path, format=None): |
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171 | """ |
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172 | Call the loader for the file type of path. |
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173 | |
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174 | Raises ValueError if no loader is available. |
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175 | May raise a loader-defined exception if loader fails. |
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176 | """ |
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177 | if format is None: |
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178 | readers = self.lookup(path) |
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179 | else: |
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180 | readers = self.readers[format] |
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181 | if readers!=None: |
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182 | for fn in readers: |
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183 | try: |
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184 | value=fn.read(path) |
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185 | self.reading= fn.__class__ |
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186 | return value |
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187 | except ValueError,msg: |
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188 | print str(msg) |
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189 | if __name__=="__main__": |
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190 | l=Loader() |
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191 | l.__setitem__() |
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192 | print "look up",l.lookup('angles_flat.png') |
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193 | print l.__getitem__('.tiff') |
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194 | print l.__contains__('.tiff') |
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195 | |
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