Python随笔(二)、python基础
源自：http://www.cnblogs.com/wupeiqi/articles/4906230.html
一、接收执行参数
sys.argv 接收执行参数的函数
#!usr/bin/env python
#-*- coding:utf-8 _*-
"""
@author:Administrator
@file: sysargv.py
@time: 2017/11/19
"""
import sys
print (sys.argv)执行结果
[root@python3 ~]# python index.py 8000
['index.py', '8000']
[root@python3 ~]# python index.py runserver
['index.py', 'runserver']
列表，元祖：
区别，列表可以被修改，元祖不能被修改，列表包含元祖
元祖的元素不能被修改，元祖的元素的元素可以被修改。如下程序所示
#!usr/bin/env python
#-*- coding:utf-8 _*-
"""
@author:Administrator
@file: tuple.py
@time: 2017/11/19
"""
t1 = (1,2,{'k1':'v1'})
#t1[2]['k1'] = 2
#print(t1)
t1[2] = 123
print(t1)执行报错：
Traceback (most recent call last):
File "C:/Users/Administrator/PycharmProjects/S12/2017-11-19/tuple.py", line 11, in <module>
t1[2] = 123
TypeError: 'tuple' object does not support item assignment
#!usr/bin/env python
#-*- coding:utf-8 _*-
"""
@author:Administrator
@file: tuple.py
@time: 2017/11/19
"""
t1 = (1,2,{'k1':'v1'})
t1[2]['k1'] = 2
print(t1)执行结果：
(1, 2, {'k1': 2})
Process finished with exit code 0
对于python,一切事物皆是对象，对象基于类创建
字符串常用功能：
- 移除空白 strip
- 分割 slipt
- 长度 len
- 索引 index
- 切片 [1:] [2:5] [:-1]
4、列表
创建列表：
123 | name_list = ['alex', 'seven', 'eric']或name_list ＝ list(['alex', 'seven', 'eric']) |
|---|
基本操作：
- 索引 index
- 追加 append
- 删除 del
- 长度 len
- 切片 [1:] [2:5] [:-1]
- 循环 for while
- 包含 in
5、元祖
创建元祖：
123 | ages = (11, 22, 33, 44, 55)或ages = tuple((11, 22, 33, 44, 55)) |
|---|
基本操作：
- 索引 index
- 切片 [1:] [2:5] [:-1]
- 循环 for while
- 长度 len
- 包含 in
6、字典（无序）
创建字典：
123 | person = {"name": "mr.wu", 'age': 18}或person = dict({"name": "mr.wu", 'age': 18}) |
|---|
常用操作：
- 索引
- 新增
- 删除 del pop remove
- 键、值、键值对 keys values items
- 循环 for while
- 长度 len
PS：循环，range，continue 和 break
int常用功能介绍：
age = int(18)
shift + 鼠标指向int,查看内置函数
求商和余数，执行结果得到两个数的元祖
#!usr/bin/env python
#-*- coding:utf-8 _*-
"""
@author:Administrator
@file: divmod.py
@time: 2017/11/19
"""
all_list = 95
pager = 10
result = all_list.__divmod__(10)
print(result)执行结果：
(9, 5)
字典：
#!usr/bin/env python
#-*- coding:utf-8 _*-
"""
@author:Administrator
@file: dic.py
@time: 2017/11/19
"""
dic = {'k1':'v1','k2':'v2'}
print(dic['k1'])
print(dic['k2'])
#print(dic['k3'])
print(dic.get('k3','default'))for循环取k,v值
#!usr/bin/env python
#-*- coding:utf-8 _*-
"""
@author:Administrator
@file: dic.py
@time: 2017/11/19
"""
dic = {'k1':'v1','k2':'v2','k3':'v3'}
print(dic['k1'])
print(dic['k2'])
print(dic['k3'])
for k in dic.keys():
print(k)
for v in dic.values():
print(v)
for k,v in dic.items():
print(k,v）执行结果：
v1
v2
v3
k1
k2
k3
v1
v2
v3
k1 v1
k2 v2
k3 v3
pop参数，必须指定一个值，因为字典是无序的，接上文截图
result = dic.pop('k3')
print(result)#!usr/bin/env python
#-*- coding:utf-8 _*-
"""
@author:Administrator
@file: dictionary.py
@time: 2017/11/19
"""
'''
有如下集合[11,22,33,44,55,66,77,88,99,110,121,132,143,154,165,176,187]，将所有大于66的值保存在字典的第一个key中，将小于66的值保存在第二个key的值中
即：{'k1'：大于66，'k2':小于66}
'''
dic = {}
all_list = [11,22,33,44,55,66,77,88,99,110,121,132,143,154,165,176,187]
for i in all_list:
if i > 66:
if "k1" in dic.keys():
dic["k1"].append(i)
else:
dic['k1'] = [i,]
else:
if "k2" in dic.keys():
dic["k2"].append(i)
else:
dic['k2'] = [i,]
print(dic['k1'])
print(dic['k2'])