thirdparty/pyflakes/api.py

   1 """
   2 API for the command-line I{pyflakes} tool.
   3 """
   4 from __future__ import with_statement
   5
   6 import sys
   7 import os
   8 import _ast
   9 from optparse import OptionParser
  10
  11 from pyflakes import checker, __version__
  12 from pyflakes import reporter as modReporter
  13
  14 __all__ = ['check', 'checkPath', 'checkRecursive', 'iterSourceCode', 'main']
  15
  16
  17 def check(codeString, filename, reporter=None):
  18     """
  19     Check the Python source given by C{codeString} for flakes.
  20
  21     @param codeString: The Python source to check.
  22     @type codeString: C{str}
  23
  24     @param filename: The name of the file the source came from, used to report
  25         errors.
  26     @type filename: C{str}
  27
  28     @param reporter: A L{Reporter} instance, where errors and warnings will be
  29         reported.
  30
  31     @return: The number of warnings emitted.
  32     @rtype: C{int}
  33     """
  34     if reporter is None:
  35         reporter = modReporter._makeDefaultReporter()
  36     # First, compile into an AST and handle syntax errors.
  37     try:
  38         tree = compile(codeString, filename, "exec", _ast.PyCF_ONLY_AST)
  39     except SyntaxError:
  40         value = sys.exc_info()[1]
  41         msg = value.args[0]
  42
  43         (lineno, offset, text) = value.lineno, value.offset, value.text
  44
  45         # If there's an encoding problem with the file, the text is None.
  46         if text is None:
  47             # Avoid using msg, since for the only known case, it contains a
  48             # bogus message that claims the encoding the file declared was
  49             # unknown.
  50             reporter.unexpectedError(filename, 'problem decoding source')
  51         else:
  52             reporter.syntaxError(filename, msg, lineno, offset, text)
  53         return 1
  54     except Exception:
  55         reporter.unexpectedError(filename, 'problem decoding source')
  56         return 1
  57     # Okay, it's syntactically valid.  Now check it.
  58     w = checker.Checker(tree, filename)
  59     w.messages.sort(key=lambda m: m.lineno)
  60     for warning in w.messages:
  61         reporter.flake(warning)
  62     return len(w.messages)
  63
  64
  65 def checkPath(filename, reporter=None):
  66     """
  67     Check the given path, printing out any warnings detected.
  68
  69     @param reporter: A L{Reporter} instance, where errors and warnings will be
  70         reported.
  71
  72     @return: the number of warnings printed
  73     """
  74     if reporter is None:
  75         reporter = modReporter._makeDefaultReporter()
  76     try:
  77         with open(filename, 'U') as f:
  78             codestr = f.read() + '\n'
  79     except UnicodeError:
  80         reporter.unexpectedError(filename, 'problem decoding source')
  81         return 1
  82     except IOError:
  83         msg = sys.exc_info()[1]
  84         reporter.unexpectedError(filename, msg.args[1])
  85         return 1
  86     return check(codestr, filename, reporter)
  87
  88
  89 def iterSourceCode(paths):
  90     """
  91     Iterate over all Python source files in C{paths}.
  92
  93     @param paths: A list of paths.  Directories will be recursed into and
  94         any .py files found will be yielded.  Any non-directories will be
  95         yielded as-is.
  96     """
  97     for path in paths:
  98         if os.path.isdir(path):
  99             for dirpath, dirnames, filenames in os.walk(path):
 100                 for filename in filenames:
 101                     if filename.endswith('.py'):
 102                         yield os.path.join(dirpath, filename)
 103         else:
 104             yield path
 105
 106
 107 def checkRecursive(paths, reporter):
 108     """
 109     Recursively check all source files in C{paths}.
 110
 111     @param paths: A list of paths to Python source files and directories
 112         containing Python source files.
 113     @param reporter: A L{Reporter} where all of the warnings and errors
 114         will be reported to.
 115     @return: The number of warnings found.
 116     """
 117     warnings = 0
 118     for sourcePath in iterSourceCode(paths):
 119         warnings += checkPath(sourcePath, reporter)
 120     return warnings
 121
 122
 123 def main(prog=None):
 124     parser = OptionParser(prog=prog, version=__version__)
 125     __, args = parser.parse_args()
 126     reporter = modReporter._makeDefaultReporter()
 127     if args:
 128         warnings = checkRecursive(args, reporter)
 129     else:
 130         warnings = check(sys.stdin.read(), '<stdin>', reporter)
 131     raise SystemExit(warnings > 0)