本文共 2330 字，大约阅读时间需要 7 分钟。

Python ??????????B??

Python ????????????????????????????????Python ????????????????????????????????????????? Python ?????????????????????

1. for-else????????

??? Python ????????????? else ?? if ????????else ???? for??????for-else ????????????????????

for i in [1,2,3,4]:    print(i, "??else")else:    print("??else")

?????1 ??else2 ??else3 ??else4 ??else??else

????????????????????????break?????else???

2. ???(*)????(**)

???????? Python ???????? (*) ????????????? (**) ????????????????

def multi_sum(*args):    s = 0    for item in args:        s += item    return smulti_sum(3,4,5)  # ??12

???????????????????????????????????????

def do_something(name, age, gender='?', *args, **kwds):    print("??? %s????%d????%s" % (name, age, gender))    print(args)    print(kwds)

3. ?????????????????

?????? Python ???????????????????????expression if condition else expression????

y = 5print("y?????" if y < 0 else "y??????")

?????y??????

??????????????????????????

4. with - as??????????

with ??????????????????? with ??????????????????????

with open(r"D:\CSDN\Column\temp\mpmap.py", 'r') as fp:    contents = fp.readlines()

???????? try-finally ??????????????

5. ?????????????

?????????????????????????????????????????????

a = [1,2,3,4,5]result = [i*i for i in a]

???????? for ????????????????

6. ???????????

Python ????????????????????????????

a = [0,1,2,3,4,5]a[2:4]  # [2,3]a[3:]   # [3,4,5]a[1:]   # [1,2,3,4,5]a[:]    # [0,1,2,3,4,5]

??????????????????????????????

7. lambda ??????????

lambda ??????????????????????

lambda x, y: x + y

???????????????????????????????

8. yield ?????????

yield ???????????????????????????????????

def get_square(n):    for i in range(n):        yield pow(i,2)

???????????????????????????

9. ?????????????

????????????????????????????????????

import timedef timer(func):    def wrapper(*args, **kwds):        t0 = time.time()        func(*args, **kwds)        t1 = time.time()        print('??%0.3f' % (t1-t0,))        return wrapper

???????????????????????????

10. ?? assert????????

?? assert ??????????????????

def i_want_to_sleep(delay):    assert isinstance(delay, (int, float)), '?????????????'    print('????')    time.sleep(delay)    print('???')

?????????????????????????????

??

Python ?????????????????????????????????????????????????????????????????????????? Python ??????????????????????????

转载地址：http://qesy.baihongyu.com/