wanted: regex or code to find valide def statements in a line

[Gribouillis]

Using compile() is more robust that exec()

>>> source = "def spam(ham=[n for n in range(1, dividend+1) if dividend % n == 0]):\n"
>>> source = source.rstrip('\n') + 'pass\n'
>>> result = compile(source, '<string>', mode='single')
<code object <module> at 0x7f33bbb89420, file "<string>", line 1>

Now with an invalid line

>>> source = "def spam(**ham, *eggs):\n"
>>> source = source.rstrip('\n') + 'pass\n'
>>> result = compile(source, '<string>', mode='single')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1
    def spam(**ham, *eggs):pass
                  ^
SyntaxError: invalid syntax