Problems with installing modules in Python / Visual Studio Code

Question

I want to import some modules in my virtual environment like Flask, Pandas, Matplotlib etc. But the problem is that the terminal returns me the following issue:

(env) PS C:\Users\User\Desktop\Mehr\Python\Blockchain-Course> pip install matplotlib
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/matplotlib/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/matplotlib/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/matplotlib/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/matplotlib/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/matplotlib/
Could not fetch URL https://pypi.org/simple/matplotlib/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/matplotlib/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping
ERROR: Could not find a version that satisfies the requirement matplotlib (from versions: none)
ERROR: No matching distribution found for matplotlib
WARNING: You are using pip version 21.2.3; however, version 21.3.1 is available.
You should consider upgrading via the 'C:\Users\User\Desktop\Mehr\Python\Blockchain-Course\env\Scripts\python.exe -m pip install --upgrade pip' command.

I've never had any problems with it and yesterday it worked perfectly, does someone knows what to do?

Answer 1

The problem could have been caused by the DLLs in the C:\Windows\System32 folder (eg libcrypto-1_1-x64.dll or libssl-1_1-x64.dll or others) placed there by other software.

It may be fixed installing openSSL from https://slproweb.com/products/Win32OpenSSL.html which replaces the dlls by more recent versions.

Answer 2

1. first install openssl, please refer to this page
2. install python and./configure --with-openssl=/home/username/openssl at last
3. run python -m ssl and nothing outputs, it's ok.

You can refer to this page for more details.