Python 模块

导入系统包

import sys

print(len(sys.argv));

print(sys.argv);

导入当前文件下的包

--test.py

--source

|--first.py

|--second.py

from source import first, second

字典类默认值
from collections import defaultdict
lala = defaultdict(int);
print(lala["aaa"]);

可以显示0值

还可以用函数返回内容

def getdefult():
    return "asdfdasf";
lala = defaultdict(getdefult);

print(lala["aaa"]);

计算个数可以使用以下方法

from collections import Counter
breakfast = ['spam', 'spam', 'eggs', 'spam']
breakfast_counter = Counter( breakfast)
print(breakfast_counter)

转载于:https://www.cnblogs.com/spchenjie/p/8372155.html