Simple file Operations Python modifies a file to specify a line method

Example one:
Copy the Code code as follows:

#!/usr/bin/python
Import Sys
Import re
If __name__== "__main__":
F=file ("Hi.txt", "w+")
li=["hello\n", "hi\n"]
F.writelines (LI)
F.close ()

"w+" mode: Creates a file write if there is no hi.txt and, if present, empties the Hi.txt content and writes from the new.

Example two: Modifying a file to specify a line

The method is more stupid, read the contents of the file into a list in a row, modify the specified line to assign values to the elements in the list, and after the modification, use Writelines to write the list to a new file.

Copy the Code code as follows:

#!/usr/bin/python

Import Sys,os

F=open (' Hi.txt ', ' r+ ')
Flist=f.readlines ()
flist[4]= ' hi\n '
F=open (' Hi.txt ', ' w+ ')
F.writelines (Flist)

Change the contents of Hi.txt line fifth to hi

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