How to create fake text file in Python

问题

How can I create a fake file object in Python that contains text? I'm trying to write unit tests for a method that takes in a file object and retrieves the text via readlines() then do some text manipulation. Please note I can't create an actual file on the file system. The solution has to be compatible with Python 2.7.3.

回答1:

This is exactly what StringIO/cStringIO (renamed to io.StringIO in Python 3) is for.

回答2:

Or you could implement it yourself pretty easily especially since all you need is readlines():

class FileSpoof:
     def __init__(self,my_text):
         self.my_text = my_text
     def readlines(self):
         return self.my_text.splitlines()

then just call it like:

somefake = FileSpoof("This is a bunch\nOf Text!")
print somefake.readlines()

That said the other answer is probably more correct.

回答3:

In python3, it can be as simple as

import io
file = io.StringIO("your text goes here") # takes string as arg
file.read()

In python 2.7, it can be something like:

import io
file = io.StringIO(u"your text goes here") # takes unicode as argument
file.read()

You can use the file object for testing purpose.

来源：https://stackoverflow.com/questions/11833428/how-to-create-fake-text-file-in-python