have a problem about the function of sort()

[wxde]

i want a list sorted by the lenght of str. the environment is python3.6

"strs.sort(lambda x,y:cmp(len(x),len(y)))"

the error : TypeError: must use keyword argument for key function

i don't know where is the error

[ashwek]

@wxde
try: strs.sort(key = lambda x: len(x))

[wxde]

thanks to ashwek, it work