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NotImplementedError: pseudo-class is not implemented - how to Update Python to solve
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NotImplementedError: pseudo-class is not implemented - how to Update Python to solve
hello dear Python-experts, Smile

first of all: many many thanks for this awesome forum: this is one of the best places for Python. I am glad to be part of this great forum.

on anaconda which runs on MX-Linux i have runned a parser and got back some errorlogs:

Traceback (most recent call last):

  File "/home/martin/dev/", line 57, in <module>
    soup.select_one('td:-soup-contains("Receiving") ~ td'),

  File "/home/martin/anaconda3/lib/python3.7/site-packages/bs4/", line 1749, in select_one
    value =, namespaces, 1, **kwargs)

  File "/home/martin/anaconda3/lib/python3.7/site-packages/bs4/", line 1784, in select
    results =, self, namespaces, limit, **kwargs)

  File "/home/martin/anaconda3/lib/python3.7/site-packages/soupsieve/", line 114, in select
    return compile(select, namespaces, flags, **kwargs).select(tag, limit)

  File "/home/martin/anaconda3/lib/python3.7/site-packages/soupsieve/", line 63, in compile
    return cp._cached_css_compile(pattern, namespaces, custom, flags)

  File "/home/martin/anaconda3/lib/python3.7/site-packages/soupsieve/", line 206, in _cached_css_compile
    CSSParser(pattern, custom=custom_selectors, flags=flags).process_selectors(),

  File "/home/martin/anaconda3/lib/python3.7/site-packages/soupsieve/", line 1062, in process_selectors
    return self.parse_selectors(self.selector_iter(self.pattern), index, flags)

  File "/home/martin/anaconda3/lib/python3.7/site-packages/soupsieve/", line 919, in parse_selectors
    has_selector, is_html = self.parse_pseudo_class(sel, m, has_selector, iselector, is_html)

  File "/home/martin/anaconda3/lib/python3.7/site-packages/soupsieve/", line 657, in parse_pseudo_class
    "'{}' pseudo-class is not implemented at this time".format(pseudo)
generally spoken: NotImplementedError: ':-soup-contains' pseudo-class is not implemented at this time
well i guess ( i suppose) that this error-log i get because i run older versions of python;

see what i have got at the moment - and yes: i guess i have to update python to be up to date - and to get rid of these errorlogs - is this true!?

see here the Anaconda system (version) and all the "ingredients" - like Python, VScode and Spyder... and its versions.

conda-base Python 3.7.6

Python 3.7.6 default, Jan 8 2020, 19:59:22)
Type "copyright", "credits" or "license" for more information.
IPython 7.12.0 -- An enhanced Interactive Python.

Spyder 4.0.1
The Scientific Python Development Environment |
Copyright © 2009-2019 Spyder Project Contributors and others.
Distributed under the terms of the MIT License.
Python 3.7.6 64-bit | Qt 5.9.6 | PyQt5 5.9.2 | Linux 4.19.0-6-amd64

VSCode 1.56.2

well - to avoid any issues (like the Nonimplemented-ones see above - i need to update python.
what do you say - !? How to update

at least python. Can i do this via commandline!?

i guess - i found this:

Quote:Step 1: First install the Ubuntu software properties package if it’s not already installed on your system.

$ sudo apt update
$ sudo apt install software-properties-common
Step 2: After that run the commands to add the PPA.

$ sudo add-apt-repository ppa:deadsnakes/ppa
Step 3: Finally, run below to install Python 3.8

$ sudo apt update
$ sudo apt install python3.8
You can check as below:

$ python3 --version

see below what i have got back
$ python -m pip install pip
Requirement already satisfied: pip in ./anaconda3/lib/python3.7/site-packages (20.0.2)
(base) [email protected]:~
$ python -m pip install –upgrade pip
ERROR: Invalid requirement: '–upgrade'
(base) [email protected]:~
$ python -m pip install --upgrade pip
Collecting pip
  Downloading pip-21.1.1-py3-none-any.whl (1.5 MB)
     |████████████████████████████████| 1.5 MB 439 kB/s 
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 20.0.2
    Uninstalling pip-20.0.2:
      Successfully uninstalled pip-20.0.2
Successfully installed pip-21.1.1
(base) [email protected]:~
i saw another method - here:
Quote:In LINUX, you may use the following commands:

$ sudo add-apt-repository ppa:deadsnakes/ppa
$ sudo apt update
$ sudo apt install python3.9
Then, you can check your new and existing Python installation version as commands below:

sudo apt update gives back here the folllowing:

(base) [email protected]:/home/martin# sudo apt update
OK:1 buster-updates InRelease
OK:2 buster InRelease                                                 
OK:3 buster/updates InRelease                                
OK:4 stable InRelease                                        
OK:5 buster InRelease                   
0% [Verbunden mit (] [Warten auf Kopfzeilen] [Verbunden mit packages.
OK:6 stable InRelease                                  
Ign:7 stable InRelease                                          
OK:8 stable Release                    
OK:9 any InRelease
Paketlisten werden gelesen... Fertig
Abhängigkeitsbaum wird aufgebaut.       
Statusinformationen werden eingelesen.... Fertig
Alle Pakete sind aktuell.
(base) [email protected]:/home/martin# 
(base) [email protected]:/home/martin# 
Wordpress - super toolkits a. :: und b. :: Awesome WordPress: A curated list of amazingly awesome WordPress resources and awesome python things
this is not about python version it's about soupsiеve and beautiful soup.
Also note that it may be specific to site you try to parse and soupsieve not handling it, eg. see
If you can't explain it to a six year old, you don't understand it yourself, Albert Einstein
How to Ask Questions The Smart Way: link and another link
Create MCV example
Debug small programs


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