Module review:
* Changed variable name from 'list' to 'flist'.
* Replaced "while 1" with "while True".
* Replaced if/elif/elif/elif structure with a shorter and
faster dispatch dictionary that maps attrs to methods.
* Simplified and sped comparison logic by using
ifilter, ifilterfalse, and dict.fromkeys.
* Used True and False rather than 1 and 0.
diff --git a/Lib/filecmp.py b/Lib/filecmp.py
index eaacb29..321ae0c 100644
--- a/Lib/filecmp.py
+++ b/Lib/filecmp.py
@@ -12,6 +12,7 @@
import os
import stat
import warnings
+from itertools import ifilter, ifilterfalse
__all__ = ["cmp","dircmp","cmpfiles"]
@@ -69,13 +70,13 @@
bufsize = BUFSIZE
fp1 = open(f1, 'rb')
fp2 = open(f2, 'rb')
- while 1:
+ while True:
b1 = fp1.read(bufsize)
b2 = fp2.read(bufsize)
if b1 != b2:
- return 0
+ return False
if not b1:
- return 1
+ return True
# Directory comparison class.
#
@@ -133,46 +134,12 @@
self.left_list.sort()
self.right_list.sort()
- __p4_attrs = ('subdirs',)
- __p3_attrs = ('same_files', 'diff_files', 'funny_files')
- __p2_attrs = ('common_dirs', 'common_files', 'common_funny')
- __p1_attrs = ('common', 'left_only', 'right_only')
- __p0_attrs = ('left_list', 'right_list')
-
- def __getattr__(self, attr):
- if attr in self.__p4_attrs:
- self.phase4()
- elif attr in self.__p3_attrs:
- self.phase3()
- elif attr in self.__p2_attrs:
- self.phase2()
- elif attr in self.__p1_attrs:
- self.phase1()
- elif attr in self.__p0_attrs:
- self.phase0()
- else:
- raise AttributeError, attr
- return getattr(self, attr)
-
def phase1(self): # Compute common names
- a_only, b_only = [], []
- common = {}
- b = {}
- for fnm in self.right_list:
- b[fnm] = 1
- for x in self.left_list:
- if b.get(x, 0):
- common[x] = 1
- else:
- a_only.append(x)
- for x in self.right_list:
- if common.get(x, 0):
- pass
- else:
- b_only.append(x)
+ b = dict.fromkeys(self.right_list)
+ common = dict.fromkeys(ifilter(b.has_key, self.left_list))
+ self.left_only = list(ifilterfalse(common.has_key, self.left_list))
+ self.right_only = list(ifilterfalse(common.has_key, self.right_list))
self.common = common.keys()
- self.left_only = a_only
- self.right_only = b_only
def phase2(self): # Distinguish files, directories, funnies
self.common_dirs = []
@@ -265,6 +232,17 @@
print
sd.report_full_closure()
+ methodmap = dict(subdirs=phase4,
+ same_files=phase3, diff_files=phase3, funny_files=phase3,
+ common_dirs = phase2, common_files=phase2, common_funny=phase2,
+ common=phase1, left_only=phase1, right_only=phase1,
+ left_list=phase0, right_list=phase0)
+
+ def __getattr__(self, attr):
+ if attr not in self.methodmap:
+ raise AttributeError, attr
+ self.methodmap[attr](self)
+ return getattr(self, attr)
def cmpfiles(a, b, common, shallow=1, use_statcache=None):
"""Compare common files in two directories.
@@ -297,7 +275,7 @@
# 1 for different
# 2 for funny cases (can't stat, etc.)
#
-def _cmp(a, b, sh):
+def _cmp(a, b, sh, abs=abs, cmp=cmp):
try:
return not abs(cmp(a, b, sh))
except os.error:
@@ -306,11 +284,8 @@
# Return a copy with items that occur in skip removed.
#
-def _filter(list, skip):
- result = []
- for item in list:
- if item not in skip: result.append(item)
- return result
+def _filter(flist, skip):
+ return list(ifilterfalse(skip.__contains__, flist))
# Demonstration and testing.