filecmp
— 文件和目录比较
¶
源代码： Lib/filecmp.py
filecmp
模块定义比较文件、目录的函数，具有各种可选时间/正确性权衡。为比较文件，另请参阅
difflib
模块。
filecmp
模块定义了下列函数：
filecmp.
cmp
(
f1
,
f2
,
shallow=True
)
¶
比较文件名为
f1
and
f2
，返回
True
若它们看起来相等，
False
否则。
若
shallow
is true, files with identical
os.stat()
signatures are taken to be equal. Otherwise, the contents of the files are compared.
Note that no external programs are called from this function, giving it portability and efficiency.
This function uses a cache for past comparisons and the results, with cache entries invalidated if the
os.stat()
information for the file changes. The entire cache may be cleared using
clear_cache()
.
filecmp.
cmpfiles
(
dir1
,
dir2
,
common
,
shallow=True
)
¶
Compare the files in the two directories dir1 and dir2 whose names are given by common .
Returns three lists of file names: match , mismatch , errors . match contains the list of files that match, mismatch contains the names of those that don’t, and errors lists the names of files which could not be compared. Files are listed in errors if they don’t exist in one of the directories, the user lacks permission to read them or if the comparison could not be done for some other reason.
shallow
parameter has the same meaning and default value as for
filecmp.cmp()
.
例如，
cmpfiles('a',
'b',
['c',
'd/e'])
将比较
a/c
with
b/c
and
a/d/e
with
b/d/e
.
'c'
and
'd/e'
will each be in one of the three returned lists.
filecmp.
clear_cache
(
)
¶
Clear the filecmp cache. This may be useful if a file is compared so quickly after it is modified that it is within the mtime resolution of the underlying filesystem.
3.4 版新增。
dircmp
class
¶
filecmp.
dircmp
(
a
,
b
,
ignore=None
,
hide=None
)
¶
Construct a new directory comparison object, to compare the directories
a
and
b
.
ignore
is a list of names to ignore, and defaults to
filecmp.DEFAULT_IGNORES
.
hide
is a list of names to hide, and defaults to
[os.curdir,
os.pardir]
.
dircmp
class compares files by doing
shallow
comparisons as described for
filecmp.cmp()
.
dircmp
类提供以下方法：
report
(
)
¶
打印 (到
sys.stdout
) a comparison between
a
and
b
.
report_partial_closure
(
)
¶
Print a comparison between a and b and common immediate subdirectories.
report_full_closure
(
)
¶
Print a comparison between a and b and common subdirectories (recursively).
dircmp
class offers a number of interesting attributes that may be used to get various bits of information about the directory trees being compared.
Note that via
__getattr__()
hooks, all attributes are computed lazily, so there is no speed penalty if only those attributes which are lightweight to compute are used.
left
¶
目录 a .
right
¶
目录 b .
left_list
¶
Files and subdirectories in a , filtered by hide and ignore .
right_list
¶
Files and subdirectories in b , filtered by hide and ignore .
common
¶
Files and subdirectories in both a and b .
left_only
¶
Files and subdirectories only in a .
right_only
¶
Files and subdirectories only in b .
common_dirs
¶
Subdirectories in both a and b .
common_files
¶
Files in both a and b .
common_funny
¶
Names in both
a
and
b
, such that the type differs between the directories, or names for which
os.stat()
报告错误。
same_files
¶
Files which are identical in both a and b , using the class’s file comparison operator.
diff_files
¶
Files which are in both a and b , whose contents differ according to the class’s file comparison operator.
funny_files
¶
Files which are in both a and b , but could not be compared.
subdirs
¶
A dictionary mapping names in
common_dirs
to
dircmp
对象。
Here is a simplified example of using the
subdirs
attribute to search recursively through two directories to show common different files:
>>> from filecmp import dircmp
>>> def print_diff_files(dcmp):
... 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)
...
>>> dcmp = dircmp('dir1', 'dir2')
>>> print_diff_files(dcmp)