Everything from building a Python environment to running it on Windows

When building the Python environment, I went through various articles because "authentication proxy settings, coexistence environment, and execution confirmation are required", so I think it would be good to put them together.

Introduction

Contents

The contents introduced in this article are as follows. Please skip the authentication proxy and coexistence environment construction if necessary.

• Installing Anaconda (Windows)
• Authentication proxy settings
• Building a coexistence environment for different versions
• Run the program in interactive mode
• Run Python script

Who is it for

For Python beginners who have any of the following:

• I need to use Python on my company PC (Windows)
• I want to make ** different versions coexist **, such as using both Python 2 and 3.
• Crisp ** I want to do ** from environment construction to execution confirmation **

environment

The environment whose operation has been confirmed is as follows.

• Windows10(64bit) Version 1607
• Anaconda 4.4.0 Python 3.6 Version
• Python 3.6.1 and Python 2.7.13

procedure

Install Anaconda

• Download the installer for the target OS from the Download Site. (*) Even if you are a Python2 system main user, you can use the 3 system installer.

• Kick the installed exe to proceed with the installation. __ Check "Add to environment variable PATH" Except for __, the default settings are OK.

Confirmation of setting information at the time of installation

• Launch Anaconda Prompt in the Start menu.

• Check the existing environment with the following command. "*" Is displayed in the currently operating environment.

C:\Users\User name>conda info -e

# conda environments:
#
root                  *  C:\Users\User name\Anaconda3

• Type python to see the version of Python in your current environment. From the following, you can confirm that it is Python 3.6.1.

C:\Users\User name>python
Python 3.6.1 |Anaconda 4.4.0 (64-bit)| (default, May 11 2017, 13:25:24) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

• Enter the following to exit the interactive mode once.

>>>exit() 

Authentication proxy settings

(*) If you are in an authentication proxy environment, you cannot execute "Building a coexistence environment" unless you pass the authentication first.

• Create a configuration file `.condarc``` directly under the Anaconda3 HOME directory (usually` C: \ Users \ username \ Anaconda3```).

.Describe the "user name", "password", "IP address", and "port number" used for proxy authentication in condarc as follows.[^1]

```yaml
proxy_servers:
    http: http://User name:password@IP address:port number
    https: https://User name:password@IP address:port number

(*) If you cannot create it directly, create an appropriate text file and execute the following.

#Go to the Anaconda3 HOME directory and then run
C:\Users\User name\Anaconda3 >ren <Text file name> .condarc

• Execute the following command and check if the settings are reflected.

C:\Users\User name>conda config --show

add_anaconda_token: True
...

proxy_servers:
  http: http://User name:password@IP address:port number
  https: https://User name:password@IP address:port number

...
verbosity: 0

Building a coexistence environment for different versions

• This time, as an example, a Python2.7-based environment will coexist. First, execute the following command. If you add anaconda to the end, the library automatically included when Anaconda is installed will be inherited. [^ 2]

# 2.Create a 7-series Python execution environment with the name "py27"
C:\Users\User name>conda create -n py27 python=2.7 anaconda

• Confirm that the environment has been created with the name "py27".

C:\Users\User name>conda info -e

# conda environments:
#
py27                      C:\Users\User name\Anaconda3\envs\py27
root                  *  C:\Users\User name\Anaconda3

• Enter the environment for Python2 with the activate command. [^ 3]

C:\Users\User name>activate py27
(py27) C:\Users\User name>

• Type python to see the Python version and make sure the environment is switched.

(py27) C:\Users\User name>python
Python 2.7.13 |Continuum Analytics, Inc.| (default, May 11 2017, 13:17:26) [MSC v.1500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
Anaconda is brought to you by Continuum Analytics.
Please check out: http://continuum.io/thanks and https://anaconda.org
>>>

Run the program in interactive mode

• Try to display "Hello, world!" In interactive mode while in the 2 system environment. print('hello, world!')Please enter.

>>> print('Hello, world!')
Hello, world!
>>>

I was able to confirm that "Hello, world!" Is displayed.

Run python script

• Enter the following to exit the interactive mode once.

>>>exit() 

• Prepare the following Python script and save it in an appropriate directory.

helloWorld.py

print('Hello, world!')

• Do the following and verify that "Hello, world!" Is displayed. <Script storage location>Enter the path of the script you created earlier.

(py27) C:\Users\User name>python <Script storage location>\helloWorld.py
Hello, world!

(py27) C:\Users\User name>

• Use the deactivate command to exit the 2 system environment.

(py27) C:\Users\User name>deactivate py27

C:\Users\User name>

• Type python to make sure the environment is switched.

C:\Users\User name>python
Python 3.6.1 |Anaconda 4.4.0 (64-bit)| (default, May 11 2017, 13:25:24) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

This completes the operation check of Python2 series. Following the above, you can check the operation by "Run the program in interactive mode" and "Run the Python script" in the 3rd system as well. [^ 4]

in conclusion

In this article, we have introduced the following contents.

• Installing Anaconda
• Authentication proxy settings
• Building a coexistence environment for different versions
• Run the program in interactive mode
• Run Python script

I think it was very easy from installation to execution confirmation.

For me, who mainly used Java, I was surprised that it was too easy to build a coexistence environment for different versions.

Supplement (About coexistence environment construction)

Here are some supplements related to the following commands when building a coexistence environment for different versions.

C:\Users\User name>conda create -n py27 python=2.7 anaconda

Version specification

• Of course, the version specified by ``` python merely` is OK for 3.X series.
• If you do not specify a minor version with ``` python merely`, the latest version of the target system will be installed.
• If you specify a version that is not in Anaconda Library, the following message will be output.

C:\Users\User name>conda create -n py21 python=2.1
Fetching package metadata ...........

PackageNotFoundError: Package missing in current win-64 channels:
  - python 2.1*

• The minor versions that can be specified as of 08/11/2017 are as follows.

Delete the created environment

• If you want to delete the created environment, execute the following command.

C:\Users\User name>conda remove -n <Environment name> --all

reference

• [Anaconda → Try using Jupyter Notebook \ | Mega -Takoyaki's stomach hurts](http://beer.tank.jp/anaconda-%E2%86%92-jupyter-notebook%E4%BD%BF% E3% 81% A3% E3% 81% A6% E3% 81% BF% E3% 82% 8B)
• Building a python environment for those who aim to become a data scientist 2016 -Qiita
• Installing Python environment with Anaconda -Qiita
• [Set up Anaconda on Windows-Progress Note](http://note.websmil.com/develop/anaconda%E3%82%92windows%E3%81%AB%E3%82%BB%E3%83%83% E3% 83% 88% E3% 82% A2% E3% 83% 83% E3% 83% 97)
• Prepare Python \ (Anaconda ) environment on Windows under Proxy -Qiita
• Configuration — Conda documentation
• Python 2.7.x and 3.The decisive difference of x with an example|programming| POSTD

[^ 1]: If user / password authentication is not required, delete @ and before.

[^ 2]: If you do not add anaconda to the end, install it later by yourself with `conda install``` etc. You can check what is already installed with conda list ``.

[^ 3]: `source activate``` on Mac and Linux [^ 4]: `print``` behaves differently between the 2nd and 3rd series, but this article introduces how to write it in both environments.