Unable to import required dependencies: pytz: No module named ‘pytz‘ ,dateutil: No module named【已解决】

Problem Description

When executing the program, the error is reported as follows:

Exception has occurred: ImportError

Unable to import required dependencies: pytz: No module named 'pytz' dateutil: No module named 'dateutil'

File "E:\matlab\CHB-MIT-DATA\epilepsy_eeg_classification\preprocessing.py", line 13, in <module> import pandas as pd ImportError: Unable to import required dependencies: pytz: No module named 'pytz' dateutil: No module named 'dateutil'

 direct installation

pip install --upgrade pytz

pip install --upgrade dateutil

Exception has occurred: ImportError

Unable to import required dependencies: dateutil: No module named 'dateutil'

File "E:\matlab\CHB-MIT-DATA\epilepsy_eeg_classification\preprocessing.py", line 13, in <module> import pandas as pd ImportError: Unable to import required dependencies: dateutil: No module named 'dateutil'

This dateutil could not be installed until I found this

Python installation prompt error Could not find a version that satisfies the requirement dateutil - ytkah - 博客园

(cat) PS E:\matlab> pip install --upgrade dateutil
ERROR: Could not find a version that satisfies the requirement dateutil (from versions: none)
ERROR: No matching distribution found for dateutil
(cat) PS E:\matlab> pip install dateutil
ERROR: Could not find a version that satisfies the requirement dateutil (from versions: none)
ERROR: No matching distribution found for dateutil
(cat) PS E:\matlab> pip3 install python-dateutil
Requirement already satisfied: python-dateutil in d:\program\anaconda3\envs\cat\lib\site-packages (2.8.1) 
Requirement already satisfied: six>=1.5 in d:\program\anaconda3\envs\cat\lib\site-packages (from python-dateutil) (1.16.0)
(cat) PS E:\matlab>

Although pip3 install python-dateutil is installed above. But when the program is running, it doesn't recognize it.

Pandas must rely on dateutil, and there is python-dateutil in the pip list, but it still keeps reporting errors.

I found another method to install dateutil in python 2.7 - woxin's personal space - OSCHINA - Chinese open source technology exchange community , it is said that dateutil is also installed with matplotlib, so I uninstalled matplotlib first, and then reinstalled.

pip uninstall matplotlib

pip install matplotlib

Then it is done, as shown below:

(cat) PS E:\matlab> pip uninstall matplotlib
Found existing installation: matplotlib 3.5.3
Uninstalling matplotlib-3.5.3:
  Would remove:
    d:\program\anaconda3\envs\cat\lib\site-packages\matplotlib-3.5.3-py3.7-nspkg.pth
    d:\program\anaconda3\envs\cat\lib\site-packages\matplotlib-3.5.3.dist-info\*
    d:\program\anaconda3\envs\cat\lib\site-packages\matplotlib\*
    d:\program\anaconda3\envs\cat\lib\site-packages\mpl_toolkits\axes_grid1\*
    d:\program\anaconda3\envs\cat\lib\site-packages\mpl_toolkits\axes_grid\*
    d:\program\anaconda3\envs\cat\lib\site-packages\mpl_toolkits\axisartist\*
    d:\program\anaconda3\envs\cat\lib\site-packages\mpl_toolkits\mplot3d\*
    d:\program\anaconda3\envs\cat\lib\site-packages\mpl_toolkits\tests\*
    d:\program\anaconda3\envs\cat\lib\site-packages\pylab.py
Proceed (Y/n)? y
  Successfully uninstalled matplotlib-3.5.3
(cat) PS E:\matlab> pip install matplotlib
Collecting matplotlib
  Using cached matplotlib-3.5.3-cp37-cp37m-win_amd64.whl (7.2 MB)
Requirement already satisfied: packaging>=20.0 in d:\program\anaconda3\envs\cat\lib\site-packages (from matplotlib) (21.3)
Requirement already satisfied: fonttools>=4.22.0 in d:\program\anaconda3\envs\cat\lib\site-packages (from 
matplotlib) (4.38.0)
Requirement already satisfied: numpy>=1.17 in d:\program\anaconda3\envs\cat\lib\site-packages (from matplotlib) (1.21.6)
Requirement already satisfied: cycler>=0.10 in d:\program\anaconda3\envs\cat\lib\site-packages (from matplotlib) (0.10.0)
Requirement already satisfied: kiwisolver>=1.0.1 in d:\program\anaconda3\envs\cat\lib\site-packages (from 
matplotlib) (1.3.1)
Requirement already satisfied: pillow>=6.2.0 in d:\program\anaconda3\envs\cat\lib\site-packages (from matplotlib) (8.2.0)
Requirement already satisfied: pyparsing>=2.2.1 in d:\program\anaconda3\envs\cat\lib\site-packages (from matplotlib) (2.4.7)
Collecting python-dateutil>=2.7
  Downloading python_dateutil-2.8.2-py2.py3-none-any.whl (247 kB)
     ---------------------------------------- 247.7/247.7 kB 633.2 kB/s eta 0:00:00
Requirement already satisfied: six in d:\program\anaconda3\envs\cat\lib\site-packages (from cycler>=0.10->matplotlib) (1.16.0)
Installing collected packages: python-dateutil, matplotlib
Successfully installed matplotlib-3.5.3 python-dateutil-2.8.2
(cat) PS E:\matlab>  e:; cd 'e:\matlab'; & 'D:\Program\Anaconda3\envs\cat\python.exe' 'c:\Users\asus\.vscode\extensions\ms-python.python-2022.20.2\pythonFiles\lib\python\debugpy\adapter/../..\debugpy\launcher' '14516' '--' 'e:\matlab\CHB-MIT-DATA\epilepsy_eeg_classification\preprocessing.py'

What confuses me is that the installation of matplotlib is accompanied by python-dateutil, not dateutil, but the bug is gone.