[SOLVED] Trying to use open(filename, 'w' ) gives IOError: [Errno 2] No such file or directory if directory doesn't exist

Trying to use open(filename, 'w' ) gives IOError: [Errno 2] No such file or directory if directory doesn't exist

I'm trying to create and write to a text file using Python, like so:

afile = 'D:\\temp\\test.txt'
outFile = open(afile, 'w' )
outFile.write('Test.')
outFile.close()

But I get an error like:

Error: 2
Traceback (most recent call last):
  File "<maya console>", line 1, in <module>
IOError: [Errno 2] No such file or directory: 'D:\\temp\\test.txt'

When I tried to look for a solution, most answers I found related to the slashes in the path. But I still got errors if I tried using 'D:/temp/test.txt', or r'D:\temp\test.txt' as the path.

I can, however, create a file at the root of the drive: the filenames 'D:/test.txt', 'D:\\test.txt' and r'D:\test.txt' all work.

It seems that I can't create the directory path I would like while trying to create the file.

How should I create a file at a specific path in Python? Does open() create directories if they don't exist, or do I need to explicitly create the directory path first?

Solution

You are correct in surmising that the parent directory for the file must exist in order for open to succeed. The simple way to deal with this is to make a call to os.makedirs.

From the documentation:

os.makedirs(path[, mode])

Recursive directory creation function. Like mkdir(), but makes all intermediate-level directories needed to contain the leaf directory.

So your code might run something like this:

filename = ...
dirname = os.path.dirname(filename)
if not os.path.exists(dirname):
    os.makedirs(dirname)
with open(filename, 'w'):
    ...