The following code produces a syntax error. Does anyone know why syntax errors result when using object attributes?
Python 3.7.4 (default, Jul 27 2020, 09:35:23)
[GCC 9.3.0] on linux
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>>>1.__sizeof__()
File "<stdin
1.__sizeof__()
^
SyntaxError: invalid syntax
>>>
The lexer is greedy, so it recognizes 1.__sizeof__() as float literal 1. followed by an identifier __sizeof__, rather than an int literal followed by a . operator.
$ python -m tokenize <<< "1.__sizeof__()"
1,0-1,2: NUMBER '1.'
1,2-1,12: NAME '__sizeof__'
1,12-1,13: OP '('
1,13-1,14: OP ')'
1,14-1,15: NEWLINE '\n'
2,0-2,0: ENDMARKER ''
Use parentheses to override assist the lexer:
>>> (1).__sizeof__()
28