Python修改文件往指定行插入内容的实例

class A():
  description = "abc"

description = "abc"
description = "123"

class A():
  description = "abc"
  core = True

import os

original_folder = 'E:\\code\\'


core_list = []

count = 0

# if the description is in the current line
def isMatchDescription(line_buffer):
  global core_list

  # if not catch the core_list in global, reload it.
  if not core_list:
    with open("./core.txt","r") as f:
      core_list = f.readlines()

  # if match the core description
  for des in core_list:
    if line_buffer.strip() == des.strip():
      return True
  return False



def modifySignatures():
  for dirpath, dirnames, filenames in os.walk(original_folder):
    for filename in filenames:
      modifyFile(os.path.join(dirpath,filename))

def modifyFile(filename):

  global count
  #print "Current file: %s"% filename
  lines = []
  with open(filename,"r") as f:
    lines = f.readlines()
    hit = 0

    # Enume every single line for match the description
    for index, line in enumerate(lines):
      if isMatchDescription(line):
        hit = index
        print hit
        print "Matched file:%s" % filename
        count+=1
    if hit > 0:
      lines.insert(hit-1,'  core = True\n')
    f.close()

  # Write back to file
  with open(filename,"w") as f:
    for line in lines:
      f.write(line)
    f.close()

if __name__ == '__main__':
  modifySignatures()
  print "Modified:%d"%count

class A():
  description = "abc\
  aaaaabbbbb"

class A():
  description = "abc\
  core = True
  aaaaabbbbb"

lines.insert(hit-1,' core = True\n')

class A():
  core = True
  description = "abc\
  aaaaabbbbb"