If statements and one line python scripts from command line

Question

Why do I receive a syntax error for the following one liner python code?

python -c \'import re; if True: print \"HELLO\";\'
  File \"\", line 1         


        

Answer 1

Why do I receive a syntax error for the following one liner python code?

Python grammar might forbid small_stmt ';' compound_stmt. -c argument is probably is interpreted as file_input:

fileinput: (NEWLINE | stmt)* ENDMARKER
stmt: simple_stmt | compound_stmt
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
small_stmt: import_stmt 
compound_stmt: if_stmt 

Note: there is a newline at the end of simple_stmt. if_stmt is not small_stmt it can't follow another small_stmt after ';'. A newline is necessary to introduce compound_stmt after small_stmt.

It is not an issue because bash allows multiline arguments, just don't close the opening single quote until you done e.g.:

$ python -c '
> import re
> if 1:
>   print(1)
> '
1

Note: > are printed by the shell itself here. It is not entered by hand.