Python常看函数用法，返回值类型

help(print)

Help on built-in function print in module builtins:

print(...)
    print(value, ..., sep=' ', end='\n', file=sys.stdout, flush=False)
    
    Prints the values to a stream, or to sys.stdout by default.
    Optional keyword arguments:
    file:  a file-like object (stream); defaults to the current sys.stdout.
    sep:   string inserted between values, default a space.
    end:   string appended after the last value, default a newline.
    flush: whether to forcibly flush the stream.

def times(s:str,n:int) ->str:  # 返回值为str类型
    '''
    返回n个s字符串
    '''
    return s*n
print(times('北山啦',3))

北山啦北山啦北山啦

times.__annotations__

{'s': str, 'n': int, 'return': str}

print(times.__doc__)

    返回n个s字符串

class X(object):pass
class Y(object):pass
class A(X, Y):pass
class B(Y):pass
class C(A, B):pass
 
print C.__mro__
# (<class '__main__.C'>, <class '__main__.A'>,
#  <class '__main__.X'>, <class '__main__.B'>, 
# <class '__main__.Y'>, <type 'object'>)