How to fix “ModuleNotFoundError: No module named ‘psycopg2’”

The error “ModuleNotFoundError: No module named ‘psycopg2’” can occur due to several reasons but luckily all of them can be fixed. The “psycopg2” is one of the many packages that can be installed on your system for the Python language. It is mainly an adapter for PostgreSQL databases. It works really well with multi-threaded applications to perform large amounts of “INSERT” or “UPDATE” operations.

In this article, we will provide you with the reasons that can cause the error mentioned above and also guide you on how to solve these issues.

How can the problem “ModuleNotFoundError: No module named ‘psycopg2’” be fixed?

There are numerous explanations as to what can be causing this error to occur. Some of the common reasons and their solutions are discussed below.

Reason 1: “Psycopg2” package not installed

Perhaps the biggest reason that can be causing this issue is that the module/package named “psycopg2” is not installed on your system.

Solution

So when you try to import it or use it, you will receive this error. Use the command mentioned below which will install the package:

$ sudo apt-get install python3-psycopg2

Since Python 3 is the latest version, this should install the latest psycopg2.

Reason 2: Package installed with the wrong Python version

There is a chance that you are trying to install the package to a different python version that you are using on your system. For example, you are installing “psycopg2” for Python 3 but your system is running an older version.

Solution

Check your Python version using either of these commands:

$ python -V

$ python -version

After checking the Python version, install the corresponding “psycopg2” package as shown above. This should fix the error.

Reason 3: Having a variable with the name “psycopg2”

A major reason for the error occurs when naming variables inside the Python code. If a variable is named “psycopg2” within the code, the “ModuleNotFoundError: No module named ‘psycopg2’” error can occur due to conflict with the module name.

Solution

The following solution for the issue mentioned above is very simple. We just need to make sure while writing our Python code that we do not declare any variables with the name “psycopg2”. As long as we avoid doing this, the error “ModuleNotFoundError: No module named ‘psycopg2’” will not occur.

Reason 4: Naming your Python file “psycopg2”

Similar to a variable name, it is extremely important to keep an eye while naming the python file. Like, if you name your Python file as “psycopg2.py”, it will create a conflict and the system will not recognize the original module.

Solution

Similarly to solution number 3, we can avoid this error as long as we do not name any Python files with the name “psycopg2.py”. To double-check this, we can simply search this term in the folder where our Python files are saved. That proves to us whether there is any such file saved there.

Conclusion

There are four reasons that may invoke the ModuleNotFoundError issue. The two out of four reasons refer to the installation of the module that states If the package psycopg2 is not installed or is installed with the wrong version of Python. The other two reasons include if you create any variable or python file with the name psycopg2. In this post, you have learned to fix all the above-mentioned reasons.