列表数据类型
1 列表数据类型(必考)
1.1 用途:兴趣爱好,多个女朋友
1.2 定义方式:[]内用逗号隔开多个元素,多个元素可以是任意数据类型
fangping_boy_friend_list=['ruixing','zhuping','wenyi','changyi','qiangge','ruhua']
print(fangping_boy_friend_list)
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge', 'ruhua']
fangping_boy_friend_list1=list(['ruixing','zhuping','wenyi','changyi','qiangge','ruhua'])
print(fangping_boy_friend_list1)
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge', 'ruhua']
1.3 常用操作和内置方法
1.3.1 按索引取值(正向取值+反向取值),即可存也可以取(优先掌握)
print(fangping_boy_friend_list1[0]) ## 0代表第一个字符串
print(fangping_boy_friend_list1[2])
print(fangping_boy_friend_list1[-2]) ## -2代表反向顺序的第二个字符串
ruixing
wenyi
qiangge
1.3.2 切片
[0:-1:2]‘0’代表第一个字符串,‘-1’代表往反向顺序的第一个,‘2’代表是步长:表示列表取值时每隔两个字符串取值。
fangping_boy_friend_list1=list(['ruixing','zhuping','wenyi','changyi','qiangge','ruhua'])
print(fangping_boy_friend_list1[0:6])
print(fangping_boy_friend_list1[0:-1])
print(fangping_boy_friend_list1[0:-1:1]) ##步长默认为1
print(fangping_boy_friend_list1[1:-1:2])
print(fangping_boy_friend_list1[0:-1:3])
print(fangping_boy_friend_list1[0:-1:-1]) ##[] 步长的-1也代表往反向顺序走
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge', 'ruhua']
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge']
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge']
['zhuping', 'changyi']
['ruixing', 'changyi']
[]
1.3.3 长度len(显示列表里面字符串的长度)
fangping_boy_friend_list1=list(['ruixing','zhuping','wenyi','changyi','qiangge','ruhua'])
print(len(fangping_boy_friend_list1)) #长度为6个字符串
6
1.3.4 成员运算in和not in
fangping_boy_friend_list1=list(['ruixing','zhuping','wenyi','changyi','qiangge','ruhua'])
print('biubi' in fangping_boy_friend_list1) #False
print('zhuping' in fangping_boy_friend_list1)
False
True
1.3.5 追加append (向列表添加字符串)
fangping_boy_friend_list1=list(['ruixing','zhuping','wenyi','changyi','qiangge','ruhua'])
fangping_boy_friend_list1.append('haipi') #添加一个'haipi'字符串
print(fangping_boy_friend_list1)
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge', 'ruhua', 'haipi']
1.3.6 删除del (一般通过索引去删除字符串)
fangping_boy_friend_list1=list(['ruixing','zhuping','wenyi','changyi','qiangge','ruhua'])
del fangping_boy_friend_list1[-1] #删除最后一个
print(fangping_boy_friend_list1)
del fangping_boy_friend_list1[0] #删除第一个
print(fangping_boy_friend_list1)
del fangping_boy_friend_list1[3] #删除第四个
print(fangping_boy_friend_list1)
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge']
['zhuping', 'wenyi', 'changyi', 'qiangge']
['zhuping', 'wenyi', 'changyi']
补充:当文件被删除后报错时,如何打印报错信息。(在pycharm中按CtRL + SHIFT + R可以进入全局搜索,非常实用)
SRE实战 互联网时代守护先锋,助力企业售后服务体系运筹帷幄!一键直达领取阿里云限量特价优惠。del fangping_boy_friend_list1
try:
print(fangping_boy_friend_list1)
except Exception as e:
print(f'\033[1;45m {e} \033[0m')
name 'fangping_boy_friend_list1' is not defined
1.3.7 循环(for)
print(fangping_boy_friend_list)
for i in fangping_boy_friend_list:
print(i)
['ruixing', 'zhuping', 'wenyi', 'changyi', 'qiangge', 'ruhua']
ruixing
zhuping
wenyi
changyi
qiangge
ruhua

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