Python Slice Assignment
>>> asdf = [1, 2, 3, 4]
>>> asdf[0:0] = [-1, 0]
>>> asdf
[-1, 0, 1, 2, 3, 4]
Wat
Python Formatting
>>> a = {'a': {'b': 4}}
>>> '{a["a"]["b"]}'.format(a=asdf)
*** KeyError: '"a"'
>>>'{a[a][b]}'.format(a=asdf)
'4'
Javascript Syntax
[1,2,3,4,].length // 4
[1,2,3,4,,].length // 5
27.toString() // Uncaught SyntaxError: Invalid or unexpected token
27..toString() // '27'