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1 # Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 |
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2 # For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt |
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3 |
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4 """Better tokenizing for coverage.py.""" |
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5 |
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6 import codecs |
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7 import keyword |
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8 import re |
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9 import sys |
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10 import token |
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11 import tokenize |
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12 |
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13 from coverage import env |
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14 from coverage.backward import iternext, unicode_class |
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15 from coverage.misc import contract |
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16 |
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17 |
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18 def phys_tokens(toks): |
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19 """Return all physical tokens, even line continuations. |
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20 |
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21 tokenize.generate_tokens() doesn't return a token for the backslash that |
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22 continues lines. This wrapper provides those tokens so that we can |
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23 re-create a faithful representation of the original source. |
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24 |
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25 Returns the same values as generate_tokens() |
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26 |
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27 """ |
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28 last_line = None |
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29 last_lineno = -1 |
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30 last_ttext = None |
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31 for ttype, ttext, (slineno, scol), (elineno, ecol), ltext in toks: |
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32 if last_lineno != elineno: |
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33 if last_line and last_line.endswith("\\\n"): |
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34 # We are at the beginning of a new line, and the last line |
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35 # ended with a backslash. We probably have to inject a |
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36 # backslash token into the stream. Unfortunately, there's more |
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37 # to figure out. This code:: |
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38 # |
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39 # usage = """\ |
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40 # HEY THERE |
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41 # """ |
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42 # |
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43 # triggers this condition, but the token text is:: |
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44 # |
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45 # '"""\\\nHEY THERE\n"""' |
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46 # |
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47 # so we need to figure out if the backslash is already in the |
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48 # string token or not. |
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49 inject_backslash = True |
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50 if last_ttext.endswith("\\"): |
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51 inject_backslash = False |
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52 elif ttype == token.STRING: |
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53 if "\n" in ttext and ttext.split('\n', 1)[0][-1] == '\\': |
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54 # It's a multi-line string and the first line ends with |
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55 # a backslash, so we don't need to inject another. |
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56 inject_backslash = False |
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57 if inject_backslash: |
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58 # Figure out what column the backslash is in. |
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59 ccol = len(last_line.split("\n")[-2]) - 1 |
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60 # Yield the token, with a fake token type. |
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61 yield ( |
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62 99999, "\\\n", |
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63 (slineno, ccol), (slineno, ccol+2), |
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64 last_line |
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65 ) |
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66 last_line = ltext |
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67 if ttype not in (tokenize.NEWLINE, tokenize.NL): |
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68 last_ttext = ttext |
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69 yield ttype, ttext, (slineno, scol), (elineno, ecol), ltext |
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70 last_lineno = elineno |
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71 |
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72 |
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73 @contract(source='unicode') |
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74 def source_token_lines(source): |
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75 """Generate a series of lines, one for each line in `source`. |
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76 |
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77 Each line is a list of pairs, each pair is a token:: |
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78 |
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79 [('key', 'def'), ('ws', ' '), ('nam', 'hello'), ('op', '('), ... ] |
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80 |
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81 Each pair has a token class, and the token text. |
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82 |
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83 If you concatenate all the token texts, and then join them with newlines, |
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84 you should have your original `source` back, with two differences: |
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85 trailing whitespace is not preserved, and a final line with no newline |
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86 is indistinguishable from a final line with a newline. |
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87 |
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88 """ |
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89 |
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90 ws_tokens = set([token.INDENT, token.DEDENT, token.NEWLINE, tokenize.NL]) |
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91 line = [] |
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92 col = 0 |
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93 |
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94 source = source.expandtabs(8).replace('\r\n', '\n') |
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95 tokgen = generate_tokens(source) |
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96 |
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97 for ttype, ttext, (_, scol), (_, ecol), _ in phys_tokens(tokgen): |
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98 mark_start = True |
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99 for part in re.split('(\n)', ttext): |
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100 if part == '\n': |
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101 yield line |
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102 line = [] |
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103 col = 0 |
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104 mark_end = False |
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105 elif part == '': |
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106 mark_end = False |
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107 elif ttype in ws_tokens: |
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108 mark_end = False |
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109 else: |
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110 if mark_start and scol > col: |
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111 line.append(("ws", u" " * (scol - col))) |
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112 mark_start = False |
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113 tok_class = tokenize.tok_name.get(ttype, 'xx').lower()[:3] |
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114 if ttype == token.NAME and keyword.iskeyword(ttext): |
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115 tok_class = "key" |
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116 line.append((tok_class, part)) |
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117 mark_end = True |
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118 scol = 0 |
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119 if mark_end: |
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120 col = ecol |
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121 |
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122 if line: |
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123 yield line |
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124 |
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125 |
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126 class CachedTokenizer(object): |
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127 """A one-element cache around tokenize.generate_tokens. |
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128 |
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129 When reporting, coverage.py tokenizes files twice, once to find the |
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130 structure of the file, and once to syntax-color it. Tokenizing is |
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131 expensive, and easily cached. |
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132 |
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133 This is a one-element cache so that our twice-in-a-row tokenizing doesn't |
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134 actually tokenize twice. |
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135 |
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136 """ |
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137 def __init__(self): |
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138 self.last_text = None |
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139 self.last_tokens = None |
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140 |
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141 @contract(text='unicode') |
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142 def generate_tokens(self, text): |
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143 """A stand-in for `tokenize.generate_tokens`.""" |
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144 if text != self.last_text: |
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145 self.last_text = text |
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146 readline = iternext(text.splitlines(True)) |
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147 self.last_tokens = list(tokenize.generate_tokens(readline)) |
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148 return self.last_tokens |
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149 |
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150 # Create our generate_tokens cache as a callable replacement function. |
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151 generate_tokens = CachedTokenizer().generate_tokens |
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152 |
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153 |
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154 COOKIE_RE = re.compile(r"^[ \t]*#.*coding[:=][ \t]*([-\w.]+)", flags=re.MULTILINE) |
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155 |
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156 @contract(source='bytes') |
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157 def _source_encoding_py2(source): |
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158 """Determine the encoding for `source`, according to PEP 263. |
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159 |
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160 `source` is a byte string, the text of the program. |
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161 |
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162 Returns a string, the name of the encoding. |
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163 |
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164 """ |
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165 assert isinstance(source, bytes) |
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166 |
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167 # Do this so the detect_encode code we copied will work. |
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168 readline = iternext(source.splitlines(True)) |
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169 |
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170 # This is mostly code adapted from Py3.2's tokenize module. |
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171 |
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172 def _get_normal_name(orig_enc): |
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173 """Imitates get_normal_name in tokenizer.c.""" |
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174 # Only care about the first 12 characters. |
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175 enc = orig_enc[:12].lower().replace("_", "-") |
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176 if re.match(r"^utf-8($|-)", enc): |
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177 return "utf-8" |
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178 if re.match(r"^(latin-1|iso-8859-1|iso-latin-1)($|-)", enc): |
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179 return "iso-8859-1" |
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180 return orig_enc |
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181 |
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182 # From detect_encode(): |
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183 # It detects the encoding from the presence of a UTF-8 BOM or an encoding |
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184 # cookie as specified in PEP-0263. If both a BOM and a cookie are present, |
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185 # but disagree, a SyntaxError will be raised. If the encoding cookie is an |
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186 # invalid charset, raise a SyntaxError. Note that if a UTF-8 BOM is found, |
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187 # 'utf-8-sig' is returned. |
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188 |
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189 # If no encoding is specified, then the default will be returned. |
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190 default = 'ascii' |
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191 |
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192 bom_found = False |
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193 encoding = None |
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194 |
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195 def read_or_stop(): |
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196 """Get the next source line, or ''.""" |
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197 try: |
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198 return readline() |
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199 except StopIteration: |
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200 return '' |
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201 |
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202 def find_cookie(line): |
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203 """Find an encoding cookie in `line`.""" |
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204 try: |
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205 line_string = line.decode('ascii') |
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206 except UnicodeDecodeError: |
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207 return None |
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208 |
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209 matches = COOKIE_RE.findall(line_string) |
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210 if not matches: |
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211 return None |
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212 encoding = _get_normal_name(matches[0]) |
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213 try: |
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214 codec = codecs.lookup(encoding) |
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215 except LookupError: |
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216 # This behavior mimics the Python interpreter |
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217 raise SyntaxError("unknown encoding: " + encoding) |
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218 |
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219 if bom_found: |
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220 # codecs in 2.3 were raw tuples of functions, assume the best. |
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221 codec_name = getattr(codec, 'name', encoding) |
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222 if codec_name != 'utf-8': |
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223 # This behavior mimics the Python interpreter |
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224 raise SyntaxError('encoding problem: utf-8') |
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225 encoding += '-sig' |
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226 return encoding |
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227 |
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228 first = read_or_stop() |
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229 if first.startswith(codecs.BOM_UTF8): |
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230 bom_found = True |
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231 first = first[3:] |
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232 default = 'utf-8-sig' |
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233 if not first: |
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234 return default |
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235 |
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236 encoding = find_cookie(first) |
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237 if encoding: |
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238 return encoding |
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239 |
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240 second = read_or_stop() |
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241 if not second: |
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242 return default |
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243 |
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244 encoding = find_cookie(second) |
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245 if encoding: |
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246 return encoding |
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247 |
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248 return default |
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249 |
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250 |
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251 @contract(source='bytes') |
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252 def _source_encoding_py3(source): |
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253 """Determine the encoding for `source`, according to PEP 263. |
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254 |
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255 `source` is a byte string: the text of the program. |
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256 |
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257 Returns a string, the name of the encoding. |
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258 |
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259 """ |
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260 readline = iternext(source.splitlines(True)) |
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261 return tokenize.detect_encoding(readline)[0] |
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262 |
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263 |
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264 if env.PY3: |
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265 source_encoding = _source_encoding_py3 |
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266 else: |
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267 source_encoding = _source_encoding_py2 |
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268 |
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269 |
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270 @contract(source='unicode') |
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271 def compile_unicode(source, filename, mode): |
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272 """Just like the `compile` builtin, but works on any Unicode string. |
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273 |
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274 Python 2's compile() builtin has a stupid restriction: if the source string |
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275 is Unicode, then it may not have a encoding declaration in it. Why not? |
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276 Who knows! It also decodes to utf8, and then tries to interpret those utf8 |
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277 bytes according to the encoding declaration. Why? Who knows! |
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278 |
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279 This function neuters the coding declaration, and compiles it. |
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280 |
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281 """ |
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282 source = neuter_encoding_declaration(source) |
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283 if env.PY2 and isinstance(filename, unicode_class): |
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284 filename = filename.encode(sys.getfilesystemencoding(), "replace") |
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285 code = compile(source, filename, mode) |
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286 return code |
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287 |
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288 |
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289 @contract(source='unicode', returns='unicode') |
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290 def neuter_encoding_declaration(source): |
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291 """Return `source`, with any encoding declaration neutered.""" |
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292 if COOKIE_RE.search(source): |
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293 source_lines = source.splitlines(True) |
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294 for lineno in range(min(2, len(source_lines))): |
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295 source_lines[lineno] = COOKIE_RE.sub("# (deleted declaration)", source_lines[lineno]) |
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296 source = "".join(source_lines) |
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297 return source |