build.py requires Python 2.x whose EOL date is 2020

Expected Behavior

We can build and install scratch-blocks using Python 3.x.

Actual Behavior

build.py requires to use Python 2.x. See these lines.

PEP 373 and https://pythonclock.org/ says the End Of Life date of Python 2.x is January 1st, 2020. Therefore we should use Python 3.x instead in order to enjoy official security patches quickly.

Is there any plan to update the script?

[cymplecy]

@tansly Thanks for pointer - amended package.json to use c:/python27/python.exe build.py but now getting error that it can’t find subprocess.lib

> c:/python27/python.exe build.py && webpack

Traceback (most recent call last):
  File "build.py", line 574, in <module>
    test_proc = subprocess.Popen(test_args, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
  File "c:\python27\lib\subprocess.py", line 394, in __init__
    errread, errwrite)
  File "c:\python27\lib\subprocess.py", line 644, in _execute_child
    startupinfo)
WindowsError: [Error 2] The system cannot find the file specified

[rachel-fenichel]

See https://github.com/google/blockly/pull/2123 and https://github.com/google/blockly/pull/2125