Question

I am trying to reuse an opened file which is declared inside the constructor instance of a class but I guess I am doing something logically wrong. For instance consider the following example

class Temp:
    def __init__(self):
        self.open_file_ = open('periodic_status','r')

    def function1(self):
        new_file = self.open_file_
        for i in new_file:
            print 'test1'

    def function2(self):
        for j in self.open_file_:
            print 'test2'

if __name__ == '__main__':
    obj1 = Temp()
    obj1.function1()
    obj1.function2()

In the above program I can print test1 but I am not able to print the statement test2. Can some one explain me the logic.

Thanks

Answer 1

Because your file handle has exhausted all the lines in the file. You need to rewind it in “function2” using:

f.seek(0)

to start over again

See here docs.python.org