To be exhaustive, here are some information about input and output in Python. Since we will use the Numpy methods to read and write files, you may skip this chapter at first reading.
We write or read strings to/from files (other types must be converted to strings). To write in a file:
>>> f = open('workfile', 'w') # opens the workfile file
>>> type(f)
<type 'file'>
>>> f.write('This is a test \nand another test')
>>> f.close()
To read from a file
In [1]: f = open('workfile', 'r')
In [2]: s = f.read()
In [3]: print(s)
This is a test
and another test
In [4]: f.close()
See also
For more details: https://docs.python.org/tutorial/inputoutput.html
In [6]: f = open('workfile', 'r')
In [7]: for line in f:
...: print line
...:
This is a test
and another test
In [8]: f.close()