error: could not find a version that satisfies the requirement pandas (from versions: none) code example

Example 1: ERROR: Could not find a version that satisfies the requirement cv2 (from versions: none) ERROR: No matching distribution found for cv2

#Know the reason is really dumb, because the reason is that the package of CV2 is not called cv2 but called opencv-python

pip install opencv-python

#For python3:
pip3 install opencv-python

Example 2: ERROR: Could not find a version that satisfies the requirement torch===1.4.0

The most likely reason is a 32-bit installation of python, while 
the torch libraries rely on having a 64-bit version. 
Just start python from command line and observe

C:\Users\user>python
Python 3.7.4 (tags/v3.7.4:e09359112e, Jul  8 2019, 20:34:20) 
[MSC v.1916 64 bit (AMD64)] on win32

If it shows 32, then install 64-bit python

Example 3: pip error could not find a version that satisfies the requirement

$ curl https://pypi.org

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