fileinput: inplace

if inplace is set as 1, then print will flush back the output to input file

 

def file_insert( fname, linenos = [], strings = [] ):

 

lineno = 0 # record the line no in the file 

i = 0  # record the no. in linenos

 

for line in fileinput.input( fname, inplace = 1 ):

 

lineno += 1

line = line.strip() #for print add a "/n" to each line

 

                # no finish each element in linenos

if i < len( linenos ) and linenos[i] == lineno:

 

# print "", for index not in strings

if i >= len( strings ):

 

print "/n", line

else:

print strings[i]

print line

i += 1

else:

print line

 

file_insert( "a.txt", [1,4,5], ["insert1", insert3"])