Python FileCmp
filecmp is a module for comparing files.
Contents
Usage
Clear_Cache
Clear the filecmp.cmp cache.
Cmp
Compare two files. By default a shallow comparison is used (checking type, size, and modification time). To use a deep comparison, try:
import filecmp filecmp.cmp(fn1, fn2, shallow=False)
Results are cached. If the shallow comparison keys (see above) have not changed, the cached results are used.
The function takes file names, not file objects.
CmpFiles
Compare a list of files in two directories. Returns three lists:
- filenames that matched between directories
- filenames that did not match
- filenames that raised an error while trying to compare
Note that a file not existing in one directory or the other counts as an error, not a mismatch.
For example:
import filecmp
filecmp.cmpfiles('/etc/skel', '/home/somebody', ['.profile', '.bashrc'])There is a shallow named option with the same effect as in filecmp.cmp.
DirCmp
A class for comparing two directories. All comparisons are shallow.
import filecmp filecmp.dircmp(d1, d2)
The returned object has a variety of properties that can be used for customized reporting.
Property Name |
Value |
left |
names in d1 |
right |
names in d2 |
left_list |
names in d1 filtered by hide and ignore |
right_list |
names in d2 filtered by hide and ignore |
common |
names in both d1 and d2 |
left_only |
names in d1 and not d2 |
right_only |
names in d2 and not d1 |
common_dirs |
subdirectory names in both d1 and d2 |
common_files |
filenames in both d1 and d2 |
common_funny |
filenames in both d1 and d2 but either have different file types or raised an error on examining for file type |
same_files |
filenames that match |
diff_files |
filenames that did not match |
funny_files |
filenames in both d1 and d2 but could not be compared, usually for an error that isn't applicable to common_funny |
subdirs |
mapping of common_dirs names to filecmp.dircmp instances |
The named options ignore and hide are used for filtering some of the above properties. They default to filecmp.DEFAULT_IGNORES and ['.', '..'] by default.
import filecmp
dcmp = filecmp.dircmp('/etc/skel', '/home/somebody')
for name in dcmp.diff_files:
print("diff_file %s found in %s and %s" % (name, dcmp.left, dcmp.right))
for sub_dcmp in dcmp.subdirs.values():
print_diff_files(sub_dcmp)
See also
Python filecmp module documentation
Python Module of the Day article for filecmp