Question

In my Python books and also the Python Documents this code should be enough to open a file:

f = open("file.txt", "r")

But if I do this I will get an error message telling me file.txt doesn’t exist. If I however use the whole path where file.txt is located it opens it:

 f = open("C:/Users/Me/Python/file.txt", "r")

Is there an explanation for this?

Answer 1

In short – the immediate search path (the current working directory) is where Python will look… (so on Windows – possibly it’ll assume C:\Pythonxy)

Yes, it depends on where Python/IDLE is executed… for it to use its search path:

>>> import os
>>> os.getcwd()
'/home/jon'

>>> open('testing.txt')
<open file 'testing.txt', mode 'r' at 0x7f86e140edb0>

And in a shell – changing directories… then launching Python/IDLE

jon@forseti:~$ cd /srv
jon@forseti:/srv$ idle

>>> import os
>>> os.getcwd()
'/srv'
>>> open('testing.txt')

Traceback (most recent call last):
  File "<pyshell#2>", line 1, in <module>
    open('testing.txt')
IOError: [Errno 2] No such file or directory: 'testing.txt'