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

[snippsat]

SyntaxError is different than all other error,it will fail upon the first syntax error.
This will shut down parser at a early stage and parsing to first stage(byte code) never happens.

So here is there two SyntaxError and a NameError,but as mention will it stop at first error SyntaxError and shut down.
So no more action is possible before fix this error.

def foo(:
    a = bar # NameError
    ages = {
    'pam': 24,
    'jim': 24 # SyntaxError
    'michael': 43
    }
    print(ages)

foo()

Output:
λ python error_test.py
  File "error_test.py", line 1
    def foo(:
            ^
SyntaxError: invalid syntax 

If fix the first line SyntaxError.
If will now not find the NameError first,as SyntaxError trump all other error and as mention shout down the parser.
All other errors need the parser to be finish before they are reported.
So now it jump to second SyntaxError.

def foo():
    a = bar # NameError
    ages = {
    'pam': 24,
    'jim': 24 # SyntaxError
    'michael': 43
    }
    print(ages)

foo()

Output:
λ python error_test.py
  File "error_test.py", line 6
    'michael': 43
            ^
SyntaxError: invalid syntax

An as often answered here when people post that they have SyntaxError,look at line before.

If fix SyntaxError now will the NameError get reported.

def foo():
    a = bar # NameError
    ages = {
    'pam': 24,
    'jim': 24, # Fixed
    'michael': 43
    }
    print(ages)

foo()

Output:
λ python error_test.py
Traceback (most recent call last):
  File "error_test.py", line 10, in <module>
    foo()
  File "error_test.py", line 2, in foo
    a = bar # NameError
NameError: name 'bar' is not defined