SyntaxError: Non-UTF-8 code starting with '\x90' in file C:\Python36\python.exe on line 1, but no encoding declared

Question

SyntaxError: Non-UTF-8 code starting with '\x90' in file
C:\Python36\python.exe on line 1, but no encoding declared

I don't understand why it shows me that when I want to open the interpreter. Can someone help me please?

Solution

In my case I got this error on running pyinstaller's exe file from cmd and it automatically got fixed when I ran that file by directly clicking on it NOT from cmd

So, to fix this problem don't run file from terminal/cmd, try any other way.

Comments

[christopherson]

Could you please provide what value PYTHONSTARTUP was and currently is?

[Heewoon]

Note that this is because of Python's encoding language based on "unicode-escape" when ran on the terminal. The command-line utility changes this. Double click this from File Explorer.