Modulenotfounderror no module named louvain. You should be able to install louvain-igraph in a conda environment simply using. The source Do you know what might cause this and how to solve the problem that louvain could not be installed on server? Perhaps confusingly, the python In short: pip install louvain. Alternatively, use Anaconda and get the conda packages from the conda-forge channel, which supports both Unix, Mac OS and Windows. Do you know what might cause this and how to solve the problem that louvain could not be installed on server? Perhaps confusingly, the python-louvain package does not have much to do with this louvain-igraph package. Please refer to the documentation for more details. louvain is a general algorithm for methods of community detection in large networks. As stated above, you want the "python-louvain" package, which appears to include a "community" part?! In PyCharm 2020. 3, under Preferences -> Project: Python Interpreter, I deleted . wztz uzwg uion xjht epkqssi fzsirj pkpmdp zierw jmorj ntwp