6.7 filecmp -- File and Directory Comparisons
Keywords: lib

# 6.7 `filecmp` -- File and Directory Comparisons

The `filecmp` module defines functions to compare files and directories, with various optional time/correctness trade-offs.

The `filecmp` module defines the following function:

`cmp` (f1, f2[, shallow[, use_statcache]])
  Compare the files named f1 and f2, returning `1` if they seem equal, `0` otherwise.

  Unless shallow is given and is false, files with identical `os.stat()` signatures are taken to be equal. If use_statcache is given and is true, `statcache.stat()` will be called rather then `os.stat()`; the default is to use `os.stat()`.

  Files that were compared using this function will not be compared again unless their `os.stat()` signature changes. Note that using use_statcache true will cause the cache invalidation mechanism to fail -- the stale stat value will be used from `statcache`'s cache.

  Note that no external programs are called from this function, giving it portability and efficiency.

`cmpfiles` (dir1, dir2, common[, shallow[, use_statcache]])
  Returns three lists of file names: match, mismatch, errors. match contains the list of files match in both directories, mismatch includes the names of those that don't, and errros lists the names of files which could not be compared. Files may be listed in errors because the user may lack permission to read them or many other reasons, but always that the comparison could not be done for some reason.

  The shallow and use_statcache parameters have the same meanings and default values as for `filecmp.cmp()`.

Example:

      >>> import filecmp
      >>> filecmp.cmp('libundoc.tex', 'libundoc.tex')
      1
      >>> filecmp.cmp('libundoc.tex', 'lib.tex')
      0

Subsections

- 6.7.1 The `dircmp` class