python判断key是否在字典用in不用has_key

import datetime
cur = datetime.datetime.now()

num = 1
a_list = {"a":1, "b":2, "c":3}
while num < 100000:
    if "a" in a_list:
        pass
    num += 1

now = datetime.datetime.now()
print (now - cur).total_seconds()

import datetime
cur = datetime.datetime.now()

num = 1
a_list = {"a":1, "b":2, "c":3}
while num < 100000:
    if a_list.has_key("a"):
        pass
    num += 1

now = datetime.datetime.now()
print (now - cur).total_seconds()

$python del.py
0.02399
 
$python del2.py
0.030393