python实现的用于搜索文件并进行内容替换的类实例

#!/usr/bin/python -O
# coding: UTF-8
"""
-replace string in files (recursive)
-display the difference.
v0.2
 - search_string can be a re.compile() object -> use re.sub for replacing
v0.1
 - initial version
 Useable by a small "client" script, e.g.:
-------------------------------------------------------------------------------
#!/usr/bin/python -O
# coding: UTF-8
import sys, re
#sys.path.insert(0,"/path/to/git/repro/") # Please change path
from replace_in_files import SearchAndReplace
SearchAndReplace(
 search_path = "/to/the/files/",
 # e.g.: simple string replace:
 search_string = 'the old string',
 replace_string = 'the new string',
 # e.g.: Regular expression replacing (used re.sub)
 #search_string = re.compile('{% url (.*?) %}'),
 #replace_string = "{% url 'g<1>' %}",
 search_only = True, # Display only the difference
 #search_only = False, # write the new content
 file_filter=("*.py",), # fnmatch-Filter
)
-------------------------------------------------------------------------------
:copyleft: 2009-2011 by Jens Diemer
"""
__author__ = "Jens Diemer"
__license__ = """GNU General Public License v3 or above -
 http://www.opensource.org/licenses/gpl-license.php"""
__url__ = "http://www.jensdiemer.de"
__version__ = "0.2"
import os, re, time, fnmatch, difflib
# FIXME: see http://stackoverflow.com/questions/4730121/cant-get-an-objects-class-name-in-python
RE_TYPE = type(re.compile(""))
class SearchAndReplace(object):
 def __init__(self, search_path, search_string, replace_string,
 search_only=True, file_filter=("*.*",)):
 self.search_path = search_path
 self.search_string = search_string
 self.replace_string = replace_string
 self.search_only = search_only
 self.file_filter = file_filter
 assert isinstance(self.file_filter, (list, tuple))
 # FIXME: see http://stackoverflow.com/questions/4730121/cant-get-an-objects-class-name-in-python
 self.is_re = isinstance(self.search_string, RE_TYPE)
 print "Search '%s' in [%s]..." % (
 self.search_string, self.search_path
 )
 print "_" * 80
 time_begin = time.time()
 file_count = self.walk()
 print "_" * 80
 print "%s files searched in %0.2fsec." % (
 file_count, (time.time() - time_begin)
 )
 def walk(self):
 file_count = 0
 for root, dirlist, filelist in os.walk(self.search_path):
 if ".svn" in root:
 continue
 for filename in filelist:
 for file_filter in self.file_filter:
 if fnmatch.fnmatch(filename, file_filter):
 self.search_file(os.path.join(root, filename))
 file_count += 1
 return file_count
 def search_file(self, filepath):
 f = file(filepath, "r")
 old_content = f.read()
 f.close()
 if self.is_re or self.search_string in old_content:
 new_content = self.replace_content(old_content, filepath)
 if self.is_re and new_content == old_content:
 return
 print filepath
 self.display_plaintext_diff(old_content, new_content)
 def replace_content(self, old_content, filepath):
 if self.is_re:
 new_content = self.search_string.sub(self.replace_string, old_content)
 if new_content == old_content:
 return old_content
 else:
 new_content = old_content.replace(
 self.search_string, self.replace_string
 )
 if self.search_only != False:
 return new_content
 print "Write new content into %s..." % filepath,
 try:
 f = file(filepath, "w")
 f.write(new_content)
 f.close()
 except IOError, msg:
 print "Error:", msg
 else:
 print "OK"
 print
 return new_content
 def display_plaintext_diff(self, content1, content2):
 """
 Display a diff.
 """
 content1 = content1.splitlines()
 content2 = content2.splitlines()
 diff = difflib.Differ().compare(content1, content2)
 def is_diff_line(line):
 for char in ("-", "+", "?"):
 if line.startswith(char):
 return True
 return False
 print "line | text
-------------------------------------------"
 old_line = ""
 in_block = False
 old_lineno = lineno = 0
 for line in diff:
 if line.startswith(" ") or line.startswith("+"):
 lineno += 1
 if old_lineno == lineno:
 display_line = "%4s | %s" % ("", line.rstrip())
 else:
 display_line = "%4s | %s" % (lineno, line.rstrip())
 if is_diff_line(line):
 if not in_block:
 print "..."
 # Display previous line
 print old_line
 in_block = True
 print display_line
 else:
 if in_block:
 # Display the next line aber a diff-block
 print display_line
 in_block = False
 old_line = display_line
 old_lineno = lineno
 print "..."
if __name__ == "__main__":
 SearchAndReplace(
 search_path=".",
 # e.g.: simple string replace:
 search_string='the old string',
 replace_string='the new string',
 # e.g.: Regular expression replacing (used re.sub)
 #search_string = re.compile('{% url (.*?) %}'),
 #replace_string = "{% url 'g<1>' %}",
 search_only=True, # Display only the difference
# search_only = False, # write the new content
 file_filter=("*.py",), # fnmatch-Filter
 )

希望本文所述对大家的Python程序设计有所帮助。