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python 【第三篇】函数基础

2017-04-17 12:14 260 查看

深浅拷贝

set是一个无序且不重复的元素集合
访问速度快
天生解决重复问题


#!/usr/bin/env python3
# -*- coding:utf-8 -*-
#深浅拷贝
import copy
#浅拷贝
#copy.copy()
#深拷贝
#copy.deepcopy()
#赋值

#字符串,数字,无论深拷贝浅拷贝还是赋值,永远指向内存的一块地址
a1 = "fdkoslagj"
a2 = a1
print(id(a1))
print(id(a2))

#其他,元组,列表,字典
n1 = {"k1":"wu","k2":123,"k3":["alex",456]}
n2 = n1
print(id(n1))
print(id(n2))
#浅拷贝
n3 = copy.copy(n1)
print(id(n1))
print(id(n3))

print(id(n1["k3"]))
print(id(n3["k3"]))

#深拷贝
n4 = copy.deepcopy(n1)
print(id(n1))
print(id(n4))

dic = {
"cpu":[80,],
"mem":[80,],
"dist":[80,]
}

print('before',dic)
#深拷贝,迭代拷贝
new_dic1 = copy.deepcopy(dic)
#改变内容,原变量也会变
#new_dic2 = copy.copy(dic)
new_dic1['cpu'][0]=50
print(dic)
print(new_dic1)



交集 差集 元素计数 有序字典 默认字典

#!/usr/bin/env python3
# -*- coding:utf-8 -*-

s1 = set([11,22,33])
s2 = set([22,44])

#在s1中除去s1与s2的交集
ret1 = s1.difference(s2)
#求s1和s2的差集
ret2 = s1.symmetric_difference(s2)

ret3 = s2.symmetric_difference(s1)
ret4 = s2.difference(s1)

print(ret1)
print(ret2)
print(ret3)
print(ret4)

import collections
#元素计数 对字典
obj = collections.Counter('kdfjsalgjkdlsajg:j')
print(obj)
#取前四个
ret = obj.most_common(4)
print(ret)
for item in obj.elements():
#输出所有元素
print(item)
for k,v in obj.items():
#输出计数后的元素:个数
print(k,v)

#有序字典

#将字典的key,保存在列表中

#有序字典
dic = collections.OrderedDict()
dic['k1']='v1'
dic['k2']='v2'
print(dic)
#将k1拿到最后
dic.move_to_end('k1')
print(dic)
'''
#要加参数
dic.pop('k1')
print(dic)
#移除最后一个
dic.popitem()
print(dic)
'''
dic.update({'k1':'v11','k10':'v10'})
print(dic)

#默认字典,key值对应的是一个列表
dic = collections.defaultdict(list)
dic['k1'].append('alex')
print(dic)


可命名元组,自定义索引值 双向队列 循环右移 单项队列

#!/usr/bin/env python3
# -*- coding:utf-8 -*-

import collections

#可命名元组,自定义索引值
MytupleClass = collections.namedtuple('MytupleClass',['x','y','z'])
obj = MytupleClass(11,22,33)
print(obj.x,obj.y,obj.z)

#双向队列
d = collections.deque()
d.append('1')
d.appendleft('10')
d.appendleft('1')
print(d)
r=d.count('1')
print(r)
d.extend(['xx','yy'])
print(d)
d.extendleft(['zz'])
print(d)
#循环右移
d.rotate(1)
print(d)
d.rotate(2)
print(d)
#单项队列
import queue
q = queue.Queue()
q.put('123')
print(q.qsize())
print(q.get())


邮箱测试

#!/usr/bin/env python3
# -*- coding:utf-8 -*-
'''
1.需要开启邮箱服务sendmail
2.邮箱服务器需要开启SMTP服务
'''
def sendmail():
try:
import smtplib
from email.mime.text import MIMEText
from email.utils import formataddr

msg = MIMEText('邮件内容', 'plain', 'utf-8')
msg['From'] = formataddr(["发件人", 'pythonxiao@126.com'])
msg['To'] = formataddr(["收件人", '329275108@qq.com'])
msg['Subject'] = "邮件主题"

server = smtplib.SMTP("smtp.126.com", 25)
server.login("pythonxiao@126.com", "xiaozhiqi2016")
server.sendmail('pythonxiao@126.com', [329275108@qq.com, ], msg.as_string())
server.quit()
except:
return "失败"
else:
return 'cc'

ret = sendmail(msg)
if ret == 'cc':
print("发送成功")
else:
print("发送失败")


函数参数问题 默认参数 指定参数 参数为列表 字典

#!/usr/bin/env python3
# -*- coding:utf-8 -*-

#默认参数放后边
def show(a1,a2=999):
print(a1,a2)
show(111)

#指定参数
def show1(a1,a2):
print(a1,a2)
show1(a2=123,a1=999)

#参数为列表
def show2(arg):
print(arg)
n=[11,22,33,44]
show2(n)

# *arg 输出元组类型
def show3(*arg):
print(arg,type(arg))
show3(1,33,44,55)

# **arg 输出字典类型
def show4(**arg):
print(arg,type(arg))
show4(n1=78)

# *args **kwargs
def show5(*args,**kwargs):
print(args,type(args))
print(kwargs,type(kwargs))
show5(11,22,33,n1=88,alex='sb')

#会将俩个都给*args
l = [11,33,55]
d = {'n1':88,'alex':'sb'}
show5(l,d)

#可以用一下方式实现*args -->l,**kwargs -->d
show5(*l,**d)



 字符串格式化

#字符串格式化一
s1 = "{0} is {1}"
result = s1.format('alex','2b')
print(result)

#字符串格式化二
s2 = "{name} is {acter}"
result = s2.format(name='alex',acter='sb')
print(result)

#字符串格式化三
s3 ="{name} is {acter}"
d = {'name':'alex','acter':'shab'}
result = s3.format(**d)
print(result)


lambda,bool,all,any,Excel表处理 eval, filter,map,round,zip

#字符串格式化一
s1 = "{0} is {1}"
result = s1.format('alex','2b')
print(result)

#字符串格式化二
s2 = "{name} is {acter}"
result = s2.format(name='alex',acter='sb')
print(result)

#字符串格式化三
s3 ="{name} is {acter}"
d = {'name':'alex','acter':'shab'}
result = s3.format(**d)
print(result)


文件处理

r 只读模式(默认)
w 只写模式。(不可读:不存在则创建,存在则删除内容)
a 追加模式。(可读,不存在则创建,存在则则只追加内容)
"+" 表示可同时读写某个文件

r+可读写文件,可读可写,可追加
w+写读
a+ 同a

"U"表示在读取时,可以将\r \n \r\n 自动转换成\n(与r或r+模式同使用)
rU
r+U

"b"表示处理二进制文件,(如FTP擦送上传ISO镜像文件,Linux可忽略,Windows处理二进制文件时需标注)
rb
wb
ab


View Code

#写
f = open('test.log','w',encoding='utf-8')
f.write('xuxiaopao')
f.close()
#读 read(2)是按照字符拿的
f = open('test.log','r',encoding='utf-8')
ret = f.read(5)
print(ret)
f.close()

#tell按照细节搞的,查看当前指针位置
f = open('test.log','r',encoding='utf-8')
print(f.tell())
f.read(5)
print(f.tell())
f.close()

#seek 指定当前指针位置
f = open('test.log','r',encoding='utf-8')
f.seek(3) #2会出错 ,3正常
ret = f.read(3)
print(ret)
f.close()

#truncate 只保留前边的东西,后边的不要
f = open('test.log','r+',encoding='utf-8')
f.seek(3)
#print(f.read())
f.truncate()
f.close()


  
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