read write mode python [duplicate]

Question

Possible Duplicate:
python open built-in function: difference between modes a, a+, w, w+, and r+?

try:
    f = open("file.txt", "r")
    try:
        string = f.read()
        line = f.readline()
        lines = f.readlines()
    finally:
        f.close()
except IOError:
    pass


try:
    f = open("file.txt", "w")
    try:
        f.write('blah') # Write a string to a file
        f.writelines(lines) # Write a sequence of strings to a file
    finally:
        f.close()
except IOError:
    pass

Hi,

this is mode which i can read and write file but i want to open file once and perform both read and write operation in python

Answer 1

Like in any other programming languages you can open a file in r+, w+ and a+ modes.

• r+ opens for reading and writing (no truncating, file pointer at the beginning)
• w+ opens for writing (and thus truncates the file) and reading
• a+ opens for appending (writing without truncating, only at the end of the file, and the file pointer is at the end of the file) and reading

Answer 2

From the doc:

r+: opens the file for both reading and writing