Skip to main content

Python on Windows and the PATH

Took me a few hours to track down a problem with importing win32com and getting "ImportError: DLL load failed: The specified module could not be found" which wasn't very clear. I doesn't even say what DLL it can't find!

Long story short, it boils down to python not being able to find the pywintypes25.dll, which is located in C:\Python24, but which is not in the PATH. Seems like having C:\Python25 added to PATH or some other solution would be a good idea. The problem wasn't even with the pywin32 package, which is what I expected and where I kept looking, but in the configuration and runtime environment of the python interpreter.

Comments

Anonymous said…
FileMonitor helps you
http://www.microsoft.com/technet/sysinternals/utilities/filemon.mspx
Anonymous said…
+1, had a similar problem and this helped me find the missing dll that was being searched for.
Cheers!
Ganesh Shamnur said…
It is not about the path alone:
If the current DLL being loaded refers to an additional DLL, the referred DLL needs to be present in the PYTHONPATH.
e.g:
a.dll is being loaded in python.
a.dll was created refering to b.dll.
So, make sure that both a.dll and b.dll are in the PYTHONPATH for proper loading.
Anonymous said…
Thank you for all your comments!

Had a similar problem, a dll (in PYTHONPATH) was loading an additional dll - it did not show it's name. I used Process Monitor (the new FileMonitor) to find out what that missing file was.
Ramprasad N said…
When I get the error "ImportError: DLL load failed: The specified module could not be found." in python, how can I know which dll it is searching for?
I dont know whether the reply will automatically reach my mail inbox. so please also mail me the reply to ramprasad85 at gmail.com

Thanks you
Anonymous said…
I'm not sure how old these comments are, but I'll add a comment since this is the first response in google for "python dll load failed."

I was able to fix this by importing pywintypes before win32api in the file that was producing the error. Give this a try, it fixed the problem for me...I guess we'll see if it causes a problem somewhere else...
Christopher said…
the pywintypes worked for me as well. Python3.2 here.

Popular posts from this blog

Why I Switched From Git to Microsoft OneDrive

I made the unexpected move with a string of recent projects to drop Git to sync between my different computers in favor of OneDrive, the file sync offering from Microsoft. Its like Dropbox, but "enterprise."

Feeling a little ashamed at what I previously would have scoffed at should I hear of it from another developer, I felt a little write up of the why and the experience could be a good idea. Now, I should emphasize that I'm not dropping Git for all my projects, just specific kinds of projects. I've been making this change in habit for projects that are just for me, not shared with anyone else. It has been especially helpful in projects I work on sporadically. More on why a little later.

So, what drove me away from Git, exactly?

On the smallest projects, like game jam hacks, I just wanted to code. I didn't want to think about revisions and commit messages. I didn't need branching or merges. I didn't even need to rollback to another version, ever. I just …

Respect and Code Reviews

Code Reviews in a development team only function best, or possible at all, when everyone approaches them with respect. That’s something I’ve usually taken for granted because I’ve had the opportunity to work with amazing developers who shine not just in their technical skills but in their interpersonal skills on a team. That isn’t always the case, so I’m going to put into words something that often exists just in assumptions.
You have to respect your code. This is first only because the nature and intent of code reviews are to safeguard the quality of your code, so even having code reviews demonstrates a baseline of respect for that code. But, maybe not everyone on the team has the same level of respect or entered a team with existing review traditions that they aren’t acquainted with.
There can be culture shock when you enter a team that’s really heavy on code reviews, but also if you enter a team or interact with a colleague who doesn’t share that level of respect for the process or…

CARDIAC: The Cardboard Computer

I am just so excited about this.


CARDIAC. The Cardboard Computer. How cool is that? This piece of history is amazing and better than that: it is extremely accessible. This fantastic design was built in 1969 by David Hagelbarger at Bell Labs to explain what computers were to those who would otherwise have no exposure to them. Miraculously, the CARDIAC (CARDboard Interactive Aid to Computation) was able to actually function as a slow and rudimentary computer. 
One of the most fascinating aspects of this gem is that at the time of its publication the scope it was able to demonstrate was actually useful in explaining what a computer was. Could you imagine trying to explain computers today with anything close to the CARDIAC?

It had 100 memory locations and only ten instructions. The memory held signed 3-digit numbers (-999 through 999) and instructions could be encoded such that the first digit was the instruction and the second two digits were the address of memory to operate on. The only re…