基本数据类型
- 整数 - 布尔值 - 字符串 - 列表 - 元组 - 字典 - 集合
一、字符串：
capitalize() :字符串首字母变大写
user_name = "sunChangxing" user_name.capitalize() #字符串首字母变大写 print(user_name)casefold() #将所有大写转换为小写（原字符串不变）
user_name = "sunChaNgxing" v = user_name.casefold() #将所有大写转换为小写（原字符串不变） casefold()更高级些不仅仅局限于英文的大小写转换，支持其他语言。 print(user_name) print(v) user_name = "sunChaNgxing" v = user_name.lower() #将所有大写转换为小写（原字符串不变） print(user_name) print(v) center(self, width, fillchar=None) #文本居中 user_name = "sunChaNgxing" v = user_name.center(20) print(user_name) 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） print(v) v = user_name.center(20,'@') print(user_name) print(v)count(self, sub, start=None, end=None): #表示传入字符在字符串中出现次数
user_name = "sunChaNgxing" v = user_name.count('n') print(v) v = user_name.count('n',2,10) print(v)endswith(self, suffix, start=None, end=None): #是否以什么结尾
user_name = "sunChaNgxing" v = user_name.endswith('g') print(v)startswith(self, prefix, start=None, end=None):#是否以什么开头
user_name = "sunChaNgxing" v = user_name.startswith('s',2,10) print(v)encode : #欠着
user_name = "sunChaNgxing" user_name.encode()expandtabs(self, tabsize=8): #替换制表符 (指定替换宽度包含前面的字符)
user_name = "su\tnC\tha\nNg\txi\tng" v = user_name.expandtabs(5) print(user_name) print(v)find(self, sub, start=None, end=None): 找到指定子序列的索引位置：不存在返回-1 （常用这个）&&
index(self, sub, start=None, end=None): 找到指定子序列的索引位置：不存在报错
user_name = "sunChaNgxing" v = user_name.find('N',4,8) print(v) user_name = "sunChaNgxing" v = user_name.index('N',4,8) print(v)format(self, *args, **kwargs): && format_map(self, mapping): 字符串格式化
user_name = "北凉参{0}百万户，其中多少{1}衣裹{2}骨？" v = user_name.format("差","铁","枯") print(v) user_name = "北凉参{name}百万户，其中多少{age}衣裹{sex}骨？" v = user_name.format(name='差',age='铁',sex='枯') print(v) user_name = "北凉参{name}百万户，其中多少{age}衣裹{sex}骨？" v = user_name.format_map({'name':'铁','age':'铁','sex':'枯' }) print(v)isalnum(self): #是否是数字、汉字 isalpha() ：是否是汉字
user_name = '123123asd嘿嘿嘿' v = user_name.isalpha() 汉字 print(v) v1 = user_name.isalnum() 数字，汉字 print(v1)isdecimal(self):#只能判断阿拉伯数字123... isdigit(self):#阿拉伯 和 ②这类 isnumeric(self):#'123'，'二'，'②' 判断是否是数字
num = '123②二' v1 = num.isdecimal() # '123' v2 = num.isdigit() # '123'，'②' v3 = num.isnumeric() # '123'，'二'，'②' print(v1,v2,v3) isidentifier(self):判断是否为Python中的标识符 user_name = 'user_name' v = user_name.isidentifier() print(v)islower(self): 是否全部为小写 & isupper(self): 是否全部为大写
user_name = 'wangbaDa' v = user_name.islower() print(v) v1 = user_name.isupper() print(v1)isspace(self): 是否全部为空格
name = ' ' v = name.isspace() print(v)join(self, iterable):元素拼接（元素字符串）
name = 'alex' v = "_".join(name) # 内部循环每个元素 print(v)ljust(self, width, fillchar=None): rjust(self, width, fillchar=None): 左右填充
name = 'alex' v = name.rjust(20,'*') print(v)##### 字符串功能总结(常用)：
name = 'alex'name.upper()name.lower()name.split()name.find()name.strip()name.startswith()name.format()name.replace()"alex".join(["aa",'bb'])# ########################################## 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,-1v = ""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) ######################################## tuple：元组,不可被修改的列表；不可变类型 #1. 获取个数 user_tuple = ('alex','eric','seven','alex') v = user_tuple.count('alex') print(v) 2.获取值的第一个索引位置 user_tuple = ('alex','eric','seven','alex') 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,1dic = {'k1':'v1'}del dic['k1']布尔值：1 True0 Falsebool(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)转载于:https://www.cnblogs.com/scxbk/p/6830169.html
