首页 > 代码库 > python Day02

python Day02

str
name1 = "huangzhong1" str类的对象,
name1.split()
name1.strip()

name2 = "huangzhong2"
name2.split()
name2.strip()
name3 = "huangzhong3"
name3.split()
name3.strip()

int
num = 19

list
li = [1,2,3,43]

dict
dic = {‘k1‘: ‘v1‘}

########################################## str 字符串 ##########################################
name = ‘alex‘ # str类的对象
1. capitalize 字符串首字母大写
自身不变,会生成一个新的值
v = name.capitalize() # 自动找到name关联的str类,执行其中的capitalize技能
print(name)
print(v)

2. 将所有大小变小写,casefold牛逼,德语...
name = ‘AleX‘
v = name.casefold() # 跟牛逼,德语...
print(name)
print(v)

3. 将所有大小变小写
name = ‘AleX‘
v = name.lower()
print(v)

4. 文本居中
参数1: 表示总长度
参数2:空白处填充的字符(长度为1)
name = ‘alex‘
v = name.center(20)
print(v)
v = name.center(20,‘行‘)
print(v)

5. 表示传入之在字符串中出现的次数
参数1: 要查找的值(子序列)
参数2: 起始位置(索引)
参数3: 结束位置(索引)
name = "alexasdfdsafsdfasdfaaaaaaaa"
v = name.count(‘a‘)
print(v)
v = name.count(‘df‘)
print(v)

v = name.count(‘df‘,12)
print(v)
v = name.count(‘df‘,0,15)
print(v)

6. 是否以xx结尾
name = ‘alex‘
v1 = name.endswith(‘ex‘)
print(v1)

7. 是否以xx开头
name = ‘alex‘
v2 = name.startswith(‘al‘)
print(v2)

8. encode欠

9. 找到制表符\t,进行替换(包含前面的值)
PS: \n
name = "al\te\tx\nalex\tuu\tkkk"
v = name.expandtabs(20)
print(v)

10. 找到指定子序列的索引位置:不存在返回-1
name = ‘alex‘
v = name.find(‘o‘)
print(v)
v = name.index(‘o‘)
print(v)

11.字符串格式化

tpl = "我是:%s;年龄:%s;性别:%s"

tpl = "我是:{0};年龄:{1};性别:{2}"
v = tpl.format("李杰",19,‘都行‘)
print(v)

tpl = "我是:{name};年龄:{age};性别:{gender}"
v = tpl.format(name=‘李杰‘,age=19,gender=‘随意‘)
print(v)

tpl = "我是:{name};年龄:{age};性别:{gender}"
v = tpl.format_map({‘name‘:"李杰",‘age‘:19,‘gender‘:‘中‘})
print(v)


12. 是否是数字、汉子.
name = ‘alex8汉子‘
v = name.isalnum() # 字,数字
print(v) # True
v2 = name.isalpha()#
print(v2)# False

13. 判断是否是数字
num = ‘②‘
v1 = num.isdecimal() # ‘123‘
v2 = num.isdigit() # ‘123‘,‘②‘
v3 = num.isnumeric() # ‘123‘,‘二‘,‘②‘
print(v1,v2,v3)


14. 是否是表示符
n = ‘name‘
v = n.isidentifier()
print(v)

15.是否全部是小写
name = "ALEX"
v = name.islower()
print(v)
v = name.isupper()
print(v)

16,.全部变大写,
name = ‘alex‘
v = name.upper() # lower()
print(v)

17.是否包含隐含的xx
name = "钓鱼要钓刀鱼,\n刀鱼要到岛上钓"
v = name.isprintable()
print(v)


18.是否全部是空格
name = ‘ ‘
v = name.isspace()
print(v)



19.元素拼接(元素字符串) *****
name = ‘alex‘

v = "_".join(name) # 内部循环每个元素
print(v)

name_list = [‘海峰‘,‘杠娘‘,‘李杰‘,‘李泉‘]
v = "搞".join(name_list)
print(v)

20. 左右填充
center,rjust,ljust
name = ‘alex‘
v = name.rjust(20,‘*‘)
print(v)


21. 对应关系 + 翻译
m = str.maketrans(‘aeiou‘,‘12345‘) # 对应关系

name = "akpsojfasdufasdlkfj8ausdfakjsdfl;kjer09asdf"
v = name.translate(m)
print(v)

22. 分割,保留分割的元素
content = "李泉SB刘康SB刘一"
v = content.partition(‘SB‘) # partition
print(v)

23. 替换
content = "李泉SB刘康SB刘浩SB刘一"
v = content.replace(‘SB‘,‘Love‘)
print(v)
v = content.replace(‘SB‘,‘Love‘,1)
print(v)

24,移除空白,\n,\t,自定义
name = ‘alex\t‘
v = name.strip() # 空白,\n,\t
print(v)

25. 大小写转换
name = "Alex"
v = name.swapcase()
print(v)

26. 填充0
name = "alex"
v = name.zfill(20)
print(v)

v1 = ‘alex‘
v2 = ‘eric‘

v = v1 + v2 # 执行v1的__add__功能
print(v)


##### 字符串功能总结:
name = ‘alex‘
name.upper()
name.lower()
name.split()
name.find()
name.strip()
name.startswith()
name.format()
name.replace()
"alex".join(["aa",‘bb‘])


##### 额外功能:
name = "alex"
name[0]
name[0:3]
name[0:3:2]
len(name)
for循环,每个元素是字符


练习题
name = "aleX"
a
v = name.strip()
print(v)
b
v = name.startswith(‘al‘)
print(v)
v = name.replace(‘l‘,‘p‘)
print(v)

v = name.split(‘l‘)
print(v) # 列表

**** 转换成字节 ****
name = "李杰"
v1 = name.encode(encoding=‘utf-8‘) # 字节类型
print(v1)
v2 = name.encode(encoding=‘gbk‘) # 字节类型
print(v2)


########################################## int 整数 ##########################################

1. 当前整数的二进制表示,最少位数
age = 4 # 100
print(age.bit_length())

2. 获取当前数据的字节表示
age = 15
v = age.to_bytes(10,byteorder=‘big‘)
v = age.to_bytes(10,byteorder=‘little‘)
print(v)
00000000 00001111 -> 15

########################################## bool 布尔值 ##########################################
v = 0 # 1,-1
v = ""
v = []
--> 空内容:False

########################################## list 列表 ##########################################
## int=xx; str=‘xxx‘ list=‘xx‘
user_list = [‘李泉‘,‘刘一‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
PS:
name = ‘alex‘
执行功能;
1.追加
user_list = [‘李泉‘,‘刘一‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
user_list.append(‘刘铭‘)
print(user_list)
2. 清空
user_list = [‘李泉‘,‘刘一‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
user_list.clear()
print(user_list)

3. 拷贝(浅拷贝)
user_list = [‘李泉‘,‘刘一‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
v = user_list.copy()
print(v)
print(user_list)

4. 计数
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
v = user_list.count(‘李泉‘)
print(v)

5. 扩展原列表
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
user_list.extend([‘郭少龙‘,‘郭少霞‘])
print(user_list)

6. 查找元素索引,没有报错
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
v = user_list.index(‘李海‘)
print(v)

7. 删除并且获取元素 - 索引
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
v = user_list.pop(1)
print(v)
print(user_list)

8. 删除 - 值
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
user_list.remove(‘刘一‘)
print(user_list)

9. 翻转
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,‘小龙‘] # 可变类型
user_list.reverse()
print(user_list)

10. 排序: 欠参数
nums = [11,22,3,3,9,88]
print(nums)
排序,从小到大
nums.sort()
print(nums)
从大到小
nums.sort(reverse=True)
print(nums)

##### 额外:
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,‘小龙‘]
user_list[0]
user_list[1:5:2]
del user_list[3]
for i in user_list:
print(i)
user_list[1] = ‘姜日天‘
user_list = [‘李泉‘,‘刘一‘,‘李泉‘,‘刘康‘,‘豆豆‘,[‘日天‘,‘日地‘,‘泰迪‘],‘小龙‘]


li = [‘eric‘,‘alex‘,‘tony‘]

v = len(li)
print(v)

li.append(‘seven‘)
print(li)

li.insert(0,‘Tony‘)
print(li)

li[1] = ‘Kelly‘

li.remove(‘eric‘)
print(list)

v = li.pop(1)
print(v)
print(li)

del li[2]


del li[0:2] # 0 =<x < 2
print(li)

li.reverse()
print(li)

for i in li:
print(i)

######################################### 强插:range,enumrate #########################################
1. 请输出1-10
2.7: 立即生成所有数字
range(1,11) # 生成 1,23,,4,56.10

3.x: 不会立即生成,只有循环迭代时,才一个一个生成
for i in range(1,11): #
print(i)

for i in range(1,11,2): #
print(i)

for i in range(10,0,-1): #
print(i)
# 1. 3.x 不会立生成,迭代之后才一个一个创建;
"""
- 2.7:
range()
xrange() 不会立生成,迭代之后才一个一个创建;
- 3.x
range() 不会立生成,迭代之后才一个一个创建;
"""
# 2. range: 三个参数
#
# li = [‘eric‘,‘alex‘,‘tony‘]
# # range,len,li循环
# for i in range(0,len(li)):
# ele = li[i]
# print(ele)


# li = [‘eric‘,‘alex‘,‘tony‘]
# for i in li:
# print(i)

# for i in range(0,len(li)):
# print(i+1,li[i])


# enumerate额外生成一列有序的数字
# li = [‘eric‘,‘alex‘,‘tony‘]
# for i,ele in enumerate(li,1):
# print(i,ele)
#
# v = input(‘请输入商品序号:‘)
# v = int(v)
# item = li[v-1]
# print(item)

# ######################################### tuple:元组,不可被修改的列表;不可变类型 #########################################
# user_tuple = (‘alex‘,‘eric‘,‘seven‘,‘alex‘)
# 1. 获取个数
# v = user_tuple.count(‘alex‘)
# print(v)
# 2.获取值的第一个索引位置
# v = user_tuple.index(‘alex‘)
# print(v)

####### 额外:
# user_tuple = (‘alex‘,‘eric‘,‘seven‘,‘alex‘)
# for i in user_tuple:
# print(i)

# v = user_tuple[0]

# v = user_tuple[0:2]
# print(v)

# user_tuple = (‘alex‘,‘eric‘,‘seven‘,[‘陈涛‘,‘刘浩‘,‘赵芬芬‘],‘alex‘)
# user_tuple[0] = 123 x
# user_tuple[3] = [11,22,33] x
# user_tuple[3][1] = ‘刘一‘
# print(user_tuple)

# li = [‘陈涛‘,‘刘浩‘,(‘alex‘,‘eric‘,‘seven‘),‘赵芬芬‘]
# ****** 元组最后,加逗号 ******
# li = (‘alex‘,)
# print(li)

# ######################################### dict:字典: 可变类型 #########################################

# 1. 清空、
# dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
# dic.clear()
# print(dic)

# 2. 浅拷贝
# dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
# v = dic.copy()
# print(v)

# 3. 根据key获取指定的value;不存在不报错
# dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
# v = dic.get(‘k1111‘,1111)
# print(v)
# v = dic[‘k1111‘]
# print(v)

# 4. 删除并获取对应的value值
# dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
# v = dic.pop(‘k1‘)
# print(dic)
# print(v)

# 5. 随机删除键值对,并获取到删除的键值
# dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
# v = dic.popitem()
# print(dic)
# print(v)

# k,v = dic.popitem() # (‘k2‘, ‘v2‘)
# print(dic)
# print(k,v)

# v = dic.popitem() # (‘k2‘, ‘v2‘)
# print(dic)
# print(v[0],v[1])

# 6. 增加,如果存在则不做操作
# dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
# dic.setdefault(‘k3‘,‘v3‘)
# print(dic)
# dic.setdefault(‘k1‘,‘1111111‘)
# print(dic)
# 7. 批量增加或修改
# dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
# dic.update({‘k3‘:‘v3‘,‘k1‘:‘v24‘})
# print(dic)


# dic = dict.fromkeys([‘k1‘,‘k2‘,‘k3‘],123)
# print(dic)
# dic = dict.fromkeys([‘k1‘,‘k2‘,‘k3‘],123)
# dic[‘k1‘] = ‘asdfjasldkf‘
# print(dic)

# dic = dict.fromkeys([‘k1‘,‘k2‘,‘k3‘],[1,])
# {
# k1: 123123213, # [1,2]
# k2: 123123213, # [1,]
# k3: 123123213, # [1,]
# }
# dic[‘k1‘].append(222)
# print(dic)
# ########## 额外:
# - 字典可以嵌套
# - 字典key: 必须是不可变类型
# dic = {
# ‘k1‘: ‘v1‘,
# ‘k2‘: [1,2,3,],
# (1,2): ‘lllll‘,
# 1: ‘fffffffff‘,
# 111: ‘asdf‘,
# }
# print(dic)
# key:
# - 不可变
# - True,1

# dic = {‘k1‘:‘v1‘}
# del dic[‘k1‘]

# 布尔值:
# 1 True
# 0 False
#
# bool(1111)


# ##################################### set,集合,不可重复的列表;可变类型 #####################################
# s1 = {"alex",‘eric‘,‘tony‘,‘李泉‘,‘李泉11‘}
# s2 = {"alex",‘eric‘,‘tony‘,‘刘一‘}

# 1.s1中存在,s2中不存在
# v = s1.difference(s2)
# print(v)
# #### s1中存在,s2中不存在,然后对s1清空,然后在重新复制
# s1.difference_update(s2)
# print(s1)

# 2.s2中存在,s1中不存在
# v = s2.difference(s1)
# print(v)

# 3.s2中存在,s1中不存在
# s1中存在,s2中不存在
# v = s1.symmetric_difference(s2)
# print(v)
# 4. 交集
# v = s1.intersection(s2)
# print(v)
# 5. 并集
# v = s1.union(s2)
# print(v)

# 6. 移除
# s1 = {"alex",‘eric‘,‘tony‘,‘李泉‘,‘李泉11‘}
# s1.discard(‘alex‘)
# print(s1)

# s1 = {"alex",‘eric‘,‘tony‘,‘李泉‘,‘李泉11‘}
# s1.update({‘alex‘,‘123123‘,‘fff‘})
# print(s1)
# ##### 额外:

# s1 = {"alex",‘eric‘,‘tony‘,‘李泉‘,‘李泉11‘}
# for i in s1:
# print(i)

# s1 = {"alex",‘eric‘,‘tony‘,‘李泉‘,‘李泉11‘,(11,22,33)}
# for i in s1:
# print(i)

python Day02