Python第二天
- 字符串操作
1.find
index5 = my_str.rfind('neuedu')
print(index5)
2.replace 字符串替换，若没有第三个参数，则会全部替换
name = 'hello world haha'
new_name = name.replace('ha','tong',1)
print(new_name)
price = "￥500"
price = price.replace('￥',599)
print(price)
3.split
name = 'hello world haha'
name_list = name.split(" ")
print(name_list)
name_list1 = name,split(" ",2)
name.split(" ",2)
print(name_list1)
4.join
str4 = " "
list1 = ['my','name','is','suntongtong']
my_name = str4.join(list1)
print(my_name)
5.strip
lstrip去空格，清除左边空格
rstrip 去空格，清除右侧空格
strip()删除两端的空白字符
#lstrip去空格，清除左边空格
print(new_my_str_space)
print(len(new_my_str_space))
new_str2 = new_my_str_space.lstrip()
print(new_str2)
print(len(new_str2))
#rstrip 去空格，清除右侧空格
new_str3 = new_str2.rstrip()
print(new_str3)
print(len(new_str3))
#strip()删除两端的空白字符
#\t \n
str1 = '\n\tdddddd\t'
print(new_my_str_space2)
print(len(new_my_str_space2))
new_str4 = new_my_str_space2.strip()
print(new_str4)
str2 = str1.strip()
print(len(str2))
6.split
name = 'hello world haha'
name_list = name.split(" ")
print(name_list)
name_list1 = name,split(" ",2)
name.split(" ",2)
print(name_list1)
- 以str为分隔符，分割name,如果maxsplit指定值，那么仅分割maxsplit个自字符串
my_str = 'hello world haha'
my_str2 = my_str.capitalize()
print(my_str2)
8.title
title()把字符串每个单词首字母大写
my_str3 = my_str.title()
print(my_str3)
9.startwith检测字符串是否以str为开始
my_str4= my_str.startswith('hello')
print(my_str4)
my_str5= my_str.startswith('Hello')
print(my_str5)
10.endswith()检测字符串是否以str为结尾
my_str.endswith('cpp')
my_str6 = my_str.endswith('cpp')
print(my_str6)
11.upper把字符串的所有字母变为大写
my_str7 = my_str.upper()
print(my_str7)
12.lower把字符串的所有字母变为小写
my_str8 = my_str7.lower()
print(my_str8)
ps:字符串不可变，修改之后创建了新的字符串
13.ljust/rjust 返回一个原字符串左对齐/右对齐，并用空格填充width长度的新字符串
my_str_space = 'hello'
new_my_str_space = my_str_space.rjust(10)
print(len(new_my_str_space))
print(new_my_str_space)
new_my_str_space1 = my_str_space.ljust(100)
print(new_my_str_space1)
print(len(new_my_str_space1))
14.partition 把mystr以str分割成3部分，str前，str,str后
print(my_str)
t_mystr = my_str.partition('neuedu')
print(t_mystr)#元组
15.splitlines 按照行分割，返回一个包含各行作为元素的列表
line = 'hello\nworld'
print(line)
list_line = line.splitlines()
print(list_line)
16.isalpha判断字符串是否都是字母 True
alpha = my_str.isalpha()
print(alpha)
alpha2 = 'ddddddd'
alpha3 = alpha2.isalpha()
print(alpha3)
- 列表操作
1.列表和c中的数组很像，但是，list可以存储不同类型的数据
# name_list = ['鲁班','xiaoming',1024]
# print(name_list)
# print(type(name_list))
2.访问及遍历
#访问
print(name_list[0])
#遍历
for x in name_list:
print(x)
i = 0
while i < len(name_list):
print(name_list[i])
3.添加
name_list = ['鲁班','xiaoming',1024]
print('添加前',name_list)
str = input('请输入您要添加的内容')
name_list.append(str)
print('添加后',name_list)
insert 在指定位置index前插入
a = [0,1,2]
a.insert(1,10)
print(a)
extend可将另外一个集合主意添加到列表中
a = [1, 2]
b = [3, 4]
a.append(b)
print(a)
a.extend(b)
print(a)
4.修改
name_list = ['鲁班','xiaoming',1024]
name_list[1] = '小明'
print(name_list)
5.删除
del：根据下标进行删除
pop 删除最后一个元素
remove 根据元素的值进行删除
name_list = ['鲁班','xiaoming',1024]
print('添加前',name_list)
del name_list[0]
print('删除后',name_list)
#pop 删除最后一个元素
name_list.pop()
print('删除后',name_list)
#remove 根据元素的值进行删除
name_list.remove()
print('删除后',name_list)
6.列表的排序
from modenam import name1, name2
num = randint(-10,10)#[-10,10]
print(num)
num_list = []
for i in range(10):
num_list.append(randint(1,20))
print(num_list)
num_list.sort()
print('正序排序',num_list)
num_list.sort(reverse=Ture)
print('逆序排序',num_list)
new_list = sorted(num_list)
sorted(num_list)
print(num_list)
区别
(1)sort对原来的列表进行修改排序 sorted(num_list)返回新的，原来的没有改变
(2).sort属于列表的成员方法，sorted对所有可迭代对象进行操作
7.列表里的嵌套，列表里还有列表
school_name = [['qinghua','beida'],['nankai','tianda'],['dongqin','nankai']]
print(school_name)
print('qqqqqqqqqqqqqqq')
print(school_name[0,1])
8.列表推导式 :所谓的列表推导式就是指轻量级循环创建列表
list1 = []
for _ in range(10)
list1.append('不给我鲁班我就送')
print(list1)
list2 = [i for i in range(10)]
print(list2)
list3 = ["不给我鲁班我就送"for _ in range(10)]
print(list3)
from random import randint
#生成十个元素范围在【-10,10】区间的列表
l = [randint(-10,10)for _ in range(10)]
print(l)
#选出大于等于0的数据
res = []
for x in l:
if x >= 0:
res.append(x)
print('使用for循环筛选：',res)
#循环过程中使用if
res2 = [x for x in l if x >=0]
print('使用列表解析筛选：',res2)
9.列表转化成字符串
my_list = ['welcome','to','ML','World']
my_list_to_str = str(my_list)
print(my_list_to_str)
print(' '.join(my_list))
10.列表和字符串的*
str1 = 'hehe'*3
print(str1)
list4 =['6',9,0,3,14]*5
print(list4)
- 分配工位
#一个学校，三个办公室，8位老师等待工位分配
import string.randint as randint
#定义3个办公室
offices = [[],[],[]]
#定义八位老师
names = string.ascii_uppercase[:8]
#names = list(names)
print(names)
for name in names:
#产生一个随机数【0,2】
index = randint(0,2)
offices[index]. append(name)
print(offices)
for tempNames in offices:
print('办公室{}的人数为{}'。format(i,len(tempNames)))
i += 1
for name in tempNames:
print('成员为{}'.format(name),end='')
print('-'*30)