/in/foo.c:1:1: error: unknown type name 'def'
 def countfamily(data):
 ^~~
/in/foo.c: In function 'countfamily':
/in/foo.c:1:22: error: expected declaration specifiers before ':' token
 def countfamily(data):
                      ^
/in/foo.c:1:5: warning: type of 'data' defaults to 'int' [-Wimplicit-int]
 def countfamily(data):
     ^~~~~~~~~~~
/in/foo.c:53:1: warning: control reaches end of non-void function [-Wreturn-type]
 m=change(n,dataArray)
 ^