No module named 'pandas._libs.tslib'

I faced the same error and resolved it by calling the following commands:

pip uninstall pandas  
pip install pandas
pip3 install --upgrade pandas

I faced a similar issue and solved it by manually uninstalling pandas and then installing pandas using pip. You have mentioned that you have only updated pandas. So I assume you haven't tried re-installing it.

While doing so pandas version in my environment changed from 0.23.4 to 0.24.1

My Environment :

python 3.6.7

pip 18.1

Note : I am also a beginner in Python usage. More experienced users may know a better way.

pip uninstall pandas
pip install pandas 

The above steps solved my issues and I am able to import pandas.

I checked the release notes in pandas community and it seems like the dependency on tslib has been removed. Check section 1.5 in the below link and search for tslib.

http://pandas.pydata.org/pandas-docs/version/0.24/pandas.pdf