Matches all defs, including multi-line defs:
def\s+\w+\(((?!\):).|\n)+\):
Matches all instances of ={ and =[:
=(\[|\{)
Matches all defs, including multi-line defs, containing ={ and =[:
def\s+\w+\(((?!\):)=(\[|\{)|\n)+\):
Possibly better, but absolutely horrendous:
def\s\w+\((?!\):).*(\w*=(\[|\{|\())+(?!\):).*\):