使用python修改文件并立即写回到原始位置操作(inplace读写)

import fileinput
for line in fileinput.input(r"D:\1.txt", inplace=1):
  print line.replace('d', 'b'),

def index_of_str(seq, sub_seq):
  index=[]
  n1=len(seq)
  n2=len(sub_seq)
  for i in range(n1-n2+1):
    #print('seq==%s' % (seq[i:i + n2]))
    if seq[i:i+n2]==sub_seq:
      #print('seq==%s'%(seq[i:i+n2]))
      index.append(i+1)
  print(index)
index_of_str('ATGATAGAGGGATACGGGATAG', 'GATA')
 
def index_of_str(s1, s2):
  global dex
  dex=0
  index=[]
  lt=s1.split(s2)
  print(lt)
  num=len(lt)
  for i in range(num-1):
    dex+=len(lt[i])
    index.append(dex)
    dex+=len(s2)
  print(index)
  #if len(lt)==1:
    #return -1
  #return len(lt[0])
print(index_of_str('ATGATAGAGGGATACGGGATAG', 'GATA'))