Question

I have defined a class to process a file but get the following error when I try to instantiate the class and pass the filename.
Let me know what would be the problem?

>>> class fileprocess:
...    def pread(self,filename):
...        print filename
...        f = open(filename,'w')
...        print f
>>> x = fileprocess
>>> x.pread('c:/test.txt')
Traceback (most recent call last):
  File "", line 1, in 
TypeError: unbound method pread() must be called with
fileprocess instance as first argument (got nothing instead)

Answer 1

x = fileprocess does not mean x is an instance of fileprocess. It means x is now an alias for the fileprocess class.

You need to create an instance, using the ().

x = fileprocess()
x.pread('c:/test.txt')

In addition, based on your original code, you could use x to create class instances.

x = fileprocess
f = x() # creates a fileprocess
f.pread('c:/test.txt')