python 3 列表操作，, 创建列表subje

python 3 列表操作，, 创建列表subje

创建列表subject=["Liunx","python","web","java"]

#读取列表print(subject)#打印显示['Liunx','python','web','java']#列表的切片,切片的索引是从0开始的print(subject[0])#0号索引，也就是列表的第一个元素print(subject[1])print(subject[2])print(subject[3])print(subject[1:3])#读取列表的第二个元素至第四个元素，第四个元素取不到，有头无尾print(subject[-1])#读取列表的最后一个元素print(subject[-2])#读取列表的倒数第二个元素print(subject[-3:])#读取列表的倒数第三个元素至最后一个元素#打印显示Liunxpythonwebjava['python','web']javaweb['python','web','java']

列表的追加

创建 列表 subject=["Liunx","python","web","java"]

#追加列表subject.append("php")#打印列表print(subject)['Liunx','python','web','java','php']##追加内容到指定的位置subject.insert(1,"windows")#将windows，插入到1号索引#打印列表print(subject)['Liunx','windows','python','web','java','php']#1号索引已变成Windows了subject.insert(2,"UI")#打印列表print(subject)['Liunx','windows','UI','python','web','java','php']

# 列表的删除

创建 列表 subject=['Liunx', 'windows', 'UI', 'python', 'web', 'java', 'php']

#删除指定元素subject.remove("php")#打印列表print(subject)['Liunx','Unix','UI','python','web','java']#根据索引删除delsubject[0]#删除Liunx#打印列表print(subject)['Unix','UI','python','web','java']#pop默认删除最后一个元素,此处删除javasubject.pop()#打印列表['Unix','UI','python','web']#查找某个名称的索引print(subject.index("python"))2

#统计元素的个数

创建列表subject = ['Liunx', 'windows', 'UI', 'python', 'web', 'java', 'php','python']

print(subject.count("python"))print(subject)2#列表的反转subject.reverse()print(subject)['python','php','java','web','python','UI','windows','Liunx']#列表的排序排序规则按照assci码规则subject.sort()print(subject)['Liunx','UI','java','php','python','python','web','windows']#列表的清除subject.clear()print(subject)[]

列表的拓展extend

创建列表

subject = ['Liunx', 'windows', 'UI', 'python', 'web', 'java', 'php','python']

subject2 = ["a","b","c"]

subject.extend(subject2)print(subject)print(subject2)#打印列表['Liunx','windows','UI','python','web','java','php','python','a','b','c']['a','b','c']

#列表的copy

创建列表subject = ["Liunx","python","web",["c++","ruby"],"java"]

subject=["Liunx","python","web",["c++","ruby"],"java"]subject3=subject.copy()#拷贝subject的内容#打印列表print(subject)print(subject3)['Liunx','python','web',['c++','ruby'],'java']['Liunx','python','web',['c++','ruby'],'java']#修改subject元素的内容subject[0]="GNUliunxsubject[3][0]="C++"#打印列表print(subject)print(subject3)['GNUliunx','python','web',['C++','ruby'],'java']#subject['Liunx','python','web',['C++','ruby'],'java']#subject3可以看到修改subject[0]="GNUliunx的内容没有在subject3里面生效，subject[3][0]="C++"这个元素生效。浅copy只copy一层，嵌套部分的不会被copy,只是copy了里面的内存地址，当subject[0]="GNUliunx相当于重新开辟了一块内存地址，所以subject3[0]读取的元素内容还是Liunx浅拷贝对应的是深拷贝importcopysubject=["Liunx","python","web",["c++","ruby"],"java","PHP"]#里面重新赋值subject[0]="smallliunx"subject[3][0]="C++"subject3=copy.deepcopy(subject)print(subject)print(subject3)['smallliunx','python','web',['C++','ruby'],'java','PHP']['smallliunx','python','web',['C++','ruby'],'java','PHP']

#列表的循环取值

#创建列表subject = ["Liunx","python","web",["c++","ruby"],"java","PHP"]

subject=["Liunx","python","web",["c++","ruby"],"java","PHP"]foriinsubject:print(i)#打印列表Liunxpythonweb['c++','ruby']javaPHP

Python 的列表操作至此完成。

python 3 列表操作