If the goal only is to list all the installed packages, `pip list` or `conda list` are the way to go. 

`pip freeze`, like `conda list --export`, is more for generating requirements files for your environment. For example, if you have created a package in your customized environment with certain dependencies, you can do `conda list --export &gt; requirements.txt`. When you are ready to distribute your package to other users, they can easily duplicate your environment and the associated dependencies with `conda create --name &lt;envname&gt; --file requirements.txt`.

&lt;br&gt;
The differences between `conda` and `pip` need a longer discussion. There are plenty of explanations on StackOverflow. [This article][1] by Jake VanderPlas is a great read as well.

You might also find [this table][2] useful. It lists operation equivalences between `conda`, `pip` and `virtualenv`.



  [1]: https://jakevdp.github.io/blog/2016/08/25/conda-myths-and-misconceptions/
  [2]: https://docs.conda.io/projects/conda/en/latest/commands.html#conda-vs-pip-vs-virtualenv-commands

I need to get scroll events from a div with overflow: scroll in my Angular 2 app.

It seems [onscroll event][1] do not works on Angular 2.

How could I achieve that?


  [1]: http://www.w3schools.com/jsref/event_onscroll.asp

How to get on scroll events?

I always used `git checkout -- .` to clear my working directory. I thought I read somewhere that the `--` was required to avoid git thinking you are passing parameters (or something)

Now a colleague told me I could drop the `--`, and indeed, a quick test did exactly the same.

Is there are any difference between those two commands?

PS: Asking here because `git checkout -- .` vs `git checkout .` is kind of hard to google...

&quot;git checkout --&quot; . vs git checkout

I am using both &quot;pip freeze&quot; and &quot;conda list&quot; to list the packages installed in my environment, but what are their differences?

Difference between pip freeze and conda list

<p>I am using both "pip freeze" and "conda list" to list the packages installed in my environment, but what are their differences?</p>


I&#39;ve install Python 3.4 and Python 3.6 on my local machine successfully, but am unable to install packages with ``pip3``.

When I execute `pip3 install &lt;package&gt;`, I get the following **SSL related** error:  

    pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
    Collecting &lt;package&gt;
      Could not fetch URL https://pypi.python.org/simple/&lt;package&gt;/: There was a problem confirming the ssl certificate: Can&#39;t connect to HTTPS URL because the SSL module is not available. - skipping
      Could not find a version that satisfies the requirement &lt;package&gt; (from versions: )
    No matching distribution found for &lt;package&gt;

How can I fix my Python3.x install so that I can install packages with ``pip install &lt;package&gt;``?


&quot;ssl module in Python is not available&quot; when installing package with pip3

I am new to python. Recently I got a project written by python and it requires some installation. I run below command to install but got an error.

    # pip install requirements.txt 
    Collecting requirements.txt
      Could not find a version that satisfies the requirement requirements.txt (from versions: )
    No matching distribution found for requirements.txt

I searched on google and found this link `http://stackoverflow.com/questions/28167987/python-pip-trouble-installing-from-requirements-txt` but I don&#39;t quite understand what the solution in that post.

Below is my requirements.txt file:

    # cat requirements.txt 
    ordereddict==1.1
    argparse==1.2.1
    python-dateutil==2.2
    matplotlib==1.3.1
    nose==1.3.0
    numpy==1.8.0
    pymongo==3.3.0
    psutil&gt;=2.0

Is there a easy way to install all required dependencies in this python project? 

**EDIT1**

Below is the output from `pip3 install -r requirements.txt `.

    # pip3 install -r requirements.txt 
    Requirement already satisfied: ordereddict==1.1 in /usr/local/lib/python3.5/dist-packages (from -r requirements.txt (line 1))
    Collecting argparse==1.2.1 (from -r requirements.txt (line 2))
      Using cached argparse-1.2.1.tar.gz
    Collecting python-dateutil==2.2 (from -r requirements.txt (line 3))
      Using cached python-dateutil-2.2.tar.gz
    Collecting matplotlib==1.3.1 (from -r requirements.txt (line 4))
      Using cached matplotlib-1.3.1.tar.gz
        Complete output from command python setup.py egg_info:
        ============================================================================
        Edit setup.cfg to change the build options
        
        BUILDING MATPLOTLIB
                    matplotlib: yes [1.3.1]
                        python: yes [3.5.2 (default, Nov 17 2016, 17:05:23)  [GCC
                                5.4.0 20160609]]
                      platform: yes [linux]
        
        REQUIRED DEPENDENCIES AND EXTENSIONS
                         numpy: yes [version 1.11.3]
                      dateutil: yes [using dateutil version 2.6.0]
                       tornado: yes [tornado was not found. It is required for the
                                WebAgg backend. pip/easy_install may attempt to
                                install it after matplotlib.]
                     pyparsing: yes [using pyparsing version 2.1.10]
                         pycxx: yes [Official versions of PyCXX are not compatible
                                with Python 3.x.  Using local copy]
                        libagg: yes [pkg-config information for &#39;libagg&#39; could not
                                be found. Using local copy.]
                      freetype: no  [The C/C++ header for freetype2 (ft2build.h)
                                could not be found.  You may need to install the
                                development package.]
                           png: yes [pkg-config information for &#39;libpng&#39; could not
                                be found. Using unknown version.]
        
        OPTIONAL SUBPACKAGES
                   sample_data: yes [installing]
                      toolkits: yes [installing]
                         tests: yes [using nose version 1.3.7]
        
        OPTIONAL BACKEND EXTENSIONS
                        macosx: no  [Mac OS-X only]
                        qt4agg: no  [PyQt4 not found]
                       gtk3agg: no  [gtk3agg backend does not work on Python 3]
                     gtk3cairo: no  [Requires cairo to be installed.]
                        gtkagg: no  [Requires pygtk]
                         tkagg: no  [TKAgg requires Tkinter.]
                         wxagg: no  [requires wxPython]
                           gtk: no  [Requires pygtk]
                           agg: yes [installing]
                         cairo: no  [cairo not found]
                     windowing: no  [Microsoft Windows only]
        
        OPTIONAL LATEX DEPENDENCIES
                        dvipng: no
                   ghostscript: no
                         latex: no
                       pdftops: no
        
        ============================================================================
                                * The following required packages can not be built:
                                * freetype
        
        ----------------------------------------
    Command &quot;python setup.py egg_info&quot; failed with error code 1 in /tmp/pip-build-don4ne_2/matplotlib/


I have already installed `libfreetype6-dev` but the pip command still reports missing this dependency.


    # apt-get install libfreetype6-dev
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    libfreetype6-dev is already the newest version (2.6.1-0.1ubuntu2).
    0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.

How to use requirements.txt to install all dependencies in a python project

I use python 2.7, 3.5.2 and 3.6. Normally `pip3` is installed with python3.x. But ...

The code:

    where pip3

gives me:
    
    INFO: Could not find files for the given pattern(s).

How can I fix this?

How to install pip3 on Windows?

I&#39;m trying to install spaCy using `pip install spacy` but I&#39;m getting the following error ..

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/z2W1Y.png

I have VS 2015 installed, and I have the following Python install ..

`3.5.2 |Anaconda 2.5.0 (64-bit)| (default, Jul  5 2016, 11:41:13) [MSC v.1900 64 bit (AMD64)]`

I tried the following SO solutions to no avail ..

 - https://stackoverflow.com/questions/41672714/command-cl-exe-failed-upon-pip-install-django-compressor
 - https://stackoverflow.com/questions/38059732/error-command-cl-exe-failed-no-such-file-or-directory

As well as various others. This is not a unique problem to this specific library but more generally anytime I try to install Python libraries that need C to build on Windows.

python pip on Windows - command &#39;cl.exe&#39; failed

I am trying to install a Python package with this command

    pip install &lt;name of package&gt;

I&#39;m getting permission errors and I&#39;m not sure why.  I could run it with `sudo`, but someone told me that was a bad idea, and I should use a virtualenv instead.

What is a virtualenv?  What does it do for me?

What is a virtualenv, and why should I use one?

How can I make anaconda environment file which could be use on other computers?

I exported my anaconda python environment to YML using `conda env export &gt; environment.yml`. The exported `environment.yml` contains this line `prefix: /home/superdev/miniconda3/envs/juicyenv` which maps to my anaconda&#39;s location which will be different on other&#39;s pcs.

Anaconda export Environment file

I&#39;m new to Conda package management and I want to get the latest version of Python to use f-strings in my code. Currently my version is (`python -V`):

    Python 3.5.2 :: Anaconda 4.2.0 (x86_64)

How would I upgrade to Python 3.6?

How do I upgrade to Python 3.6 with conda?

I have a conda environment named `old_name`, how can I change its name to `new_name` without breaking references?

How can I rename a conda environment?

How can a pre-existing conda environment be updated with another .yml file. This is extremely helpful when working on projects that have multiple requirement files, i.e. `base.yml, local.yml, production.yml`, etc.

For example, below is a `base.yml` file has conda-forge, conda, and pip packages:

base.yml

    name: myenv
    channels:
      - conda-forge
    dependencies:
      - django=1.10.5
      - pip:
        - django-crispy-forms==1.6.1

The actual environment is created with:
`conda env create -f base.yml`.

Later on, additional packages need to be added to `base.yml`. Another file, say `local.yml`, needs to import those updates.

Previous attempts to accomplish this include:

creating a `local.yml` file with an import definition:

    channels:

    dependencies:
      - pip:
        - boto3==1.4.4
    imports:
      - requirements/base. 

And then run the command:
`conda install -f local.yml`. 

This does not work. Any thoughts?

How to update an existing Conda environment with a .yml file

Midway through running `Conda Update --all`, the update stalled. Multiple packages had been updated. Now, when I run `conda update --all` or `conda update conda`, I get this response:

    (C:\Users\*****\AppData\Local\Continuum\Anaconda3) C:\Users\*****&gt;conda update conda
    Fetching package metadata ...

    CondaHTTPError: HTTP None None for url &lt;None&gt;
    Elapsed: None

    An HTTP error occurred when trying to retrieve this URL.
    HTTP errors are often intermittent, and a simple retry will get you on your way.
    SSLError(SSLError(SSLError(&quot;bad handshake: Error([(&#39;SSL routines&#39;, &#39;ssl3_get_server_certificate&#39;, &#39;certificate verify failed&#39;)],)&quot;,),),)

I&#39;ve repeated `conda update conda` over multiple days, with no change in results. I can see there is no HTTP, however `conda info --a` shows channel URLs.

    (C:\Users\*****\AppData\Local\Continuum\Anaconda3) C:\Users\*****&gt;conda info -a
    Current conda install:

               platform : win-64
          conda version : 4.3.13
       conda is private : False
      conda-env version : 4.3.13
    conda-build version : 2.1.5
         python version : 3.5.3.final.0
       requests version : 2.13.0
       root environment : C:\Users\*****\AppData\Local\Continuum\Anaconda3  (writable)
    default environment : C:\Users\*****\AppData\Local\Continuum\Anaconda3
       envs directories : C:\Users\*****\AppData\Local\Continuum\Anaconda3\envs
                          C:\Users\*****\AppData\Local\conda\conda\envs
                          C:\Users\*****\.conda\envs
          package cache : C:\Users\*****\AppData\Local\Continuum\Anaconda3\pkgs
                          C:\Users\*****\AppData\Local\conda\conda\pkgs
           channel URLs : https://conda.anaconda.org/anaconda-fusion/win-64
                          https://conda.anaconda.org/anaconda-fusion/noarch
                          https://repo.continuum.io/pkgs/free/win-64
                          https://repo.continuum.io/pkgs/free/noarch
                          https://repo.continuum.io/pkgs/r/win-64
                          https://repo.continuum.io/pkgs/r/noarch
                          https://repo.continuum.io/pkgs/pro/win-64
                          https://repo.continuum.io/pkgs/pro/noarch
                          https://repo.continuum.io/pkgs/msys2/win-64
                          https://repo.continuum.io/pkgs/msys2/noarch
            config file : C:\Users\*****\.condarc
           offline mode : False
             user-agent : conda/4.3.13 requests/2.13.0 CPython/3.5.3 Windows/7 Windows/6.1.7601

How do I get `conda update` to call a correct HTTP address?

Content Type	Original Author	Original Content on Stackoverflow
Question	DiveIntoML	View Question on Stackoverflow
Solution 1 - Pip	Shan Dou	View Answer on Stackoverflow

Difference between pip freeze and conda list

Pip Problem Overview

Pip Solutions

Solution 1 - Pip

"git checkout --" . vs git checkout

How to get on scroll events?

Attributions