8.5(列表,元组,字典,集合的内置方法)

复习

数字类型内置方法

整型,浮点型

作用:年龄,id 薪资等

使用方法:算术运算,比较运算

没有有序无序这一说

存一个值

不可变

字符串类型内置方法

作用:描述年龄性别

定义方法:

''   ''''   
\加字符
r

内置方法:
优先掌握:索引取值 切片 strip split 长度 成员运算 for循环

需要掌握:upper/lower startswith/endswith rstrip/lstrip rsplit isdigit/isalpha join replace

了解:find/rfind/index/rindex/count capitalize/swapcase/title center/ljust/rjust/zfill is系列

存一个值

有序

不可变
有序和无序:有索引就是有序,无索引就是无序

可变和不可变:值变id不变就是可变,值变id变就是不可变


列表类型内置方法

作用:描述多个值

定义方式:[]内添加,多个用逗号隔开

内置方法:

# # 1.索引取值
# name_list = ['nick','jason','tank','sean']
# name_list[0] = 'nick handsome'
# print(f"name_list[0]:{name_list[0]}")
# #2.切片
# name_list = ['nick','jason','tank','sean']
# print(f"name_list[0:3:2]:{name_list[0:3:2]}")
# # 3.长度
# name_list = ['nick','jason','tank','sean']
# print(f"len(name_list):{len(name_list)}")
# 4.成员运算in或not in
# name_list = ['nick','jason','tank','sean']
# print(f"'tank sb' in name_list:{'tank sb' in name_list}")
# print(f"'nick handsome' not in name_list:{'nick handsome' not in name_list}")
# # 5.追加值append
# name_list = ['nick','jason','tank','seam']
# name_list.append('tank sb')
# print(f"name_list:{name_list}")
# # 6.删除del
# name_list = ['nick','jason','tank','sean']
# del name_list[2]
# print(f"name_list:{name_list}")
# # 7.for循环
# name_list = ['nick','jason','tank','sean']
# for name in name_list:
#     print(name)
# 需要掌握
# 1.insert(插入)
# name_list = ['nick','jason','tank','sean']
# name_list.insert(1,'handsome')
# print(f"name_list:{name_list}")
# # 2.pop(删除,默认删除最后一个)
# name_list = ['nick','jason','tank','sean']
# print(f"name_list.pop(1):{name_list.pop(1)}")
# print(f"name_list:{name_list}")
# # 3.remove移除
# name_list = ['nick','jason','tank','sean']
# print(f"name_list.remove('nick):{name_list.remove('nick')}")
# print(f"name_list:{name_list}")计数
# 4.count计数
# name_list = ['nick','jason','tank','sean']
# print(f"name_list.count('nick'):{name_list.count('nick')}")
# # 5.index索引
# name_list = ['nick','jason','tank','sean']
# print(f"name_list.index('nick):{name_list.index('nick')}")
# # 6.clear清除
# name_list = ['nick','jason','tank','sean']
# name_list.clear()
# print(f"name_list:{name_list}")
# # 7.copy复制
# name_list = ['nick','jason','tank','sean']
# print(f"name_list,copy():{name_list.copy()}")
# 8.extend拓展
# name_list = ['nick','jason','tank','sean']
# name_list2 = ['nick handsome']
# name_list.extend(name_list2)
# print(f"name_list:{name_list}")
# # 9.reverse翻转
# name_list = ['nick','jason','tank','sean']
# name_list.reverse()
# print(f"name_list:{name_list}")
# # 10.sort
# name_list = ['nick','jason','tank','sean']
# name_list.sort()
# print(f"name_list:{name_list}")
# name_list.sort(reverse=True)

一次存多个值

有序

可变

元组类型内置方法

定义方式:列表中的中括号换为小括号

作用:与列表相同

内置方法:

# # 1.索引取值
# # name_tuple = ('nick','jason','tank','sean')
# # print(f"name_tuple[0]:{name_tuple[0]}")
# # 2.切片
# name_tuple = ('nick','jason','tank','sean')
# print(f"name_tuple[1,2,3]:{name_tuple[1:3:2]}")
# # 3.长度
# name_tuple = ('nick','jason','tank','sean')
# print(f"len(name_tuple):{len(name_tuple)}")
# # 4.成员运算
# name_tuple = ('nick','jason','tank','sean')
# print(f"'nick' in name_tuple:{'nick' in name_tuple}")
# # 5.循环
# name_tuple = ('nick','jason','tank','sean')
# for name in name_tuple:
#     print(name)
# #6.count()计数
# name_tuple = ('nick','jason','tank','sean')
# print(f"name_tuple.count('nick'):{name_tuple.count('nick')}")
# # 7.index
# name_tuple = ('nick','jason','tank','sean')

一次存多个值

有序

没有可变不可变这一说

元组与列表的不同

元组无法修改,元组在定义的时候元素个数与值就固定了,所以没有可变不可变这一说,早起用来减少内存占用,现在毫无用处

字典类型内置方法

作用:为值添加描述信息并使用

定义方式:{}内以逗号隔开加入键值对

内置方法:

# # 1.索引取值
# # name_tuple = ('nick','jason','tank','sean')
# # print(f"name_tuple[0]:{name_tuple[0]}")
# # 2.切片
# name_tuple = ('nick','jason','tank','sean')
# print(f"name_tuple[1,2,3]:{name_tuple[1:3:2]}")
# # 3.长度
# name_tuple = ('nick','jason','tank','sean')
# print(f"len(name_tuple):{len(name_tuple)}")
# # 4.成员运算
# name_tuple = ('nick','jason','tank','sean')
# print(f"'nick' in name_tuple:{'nick' in name_tuple}")
# # 5.循环
# name_tuple = ('nick','jason','tank','sean')
# for name in name_tuple:
#     print(name)
# #6.count()计数
# name_tuple = ('nick','jason','tank','sean')
# print(f"name_tuple.count('nick'):{name_tuple.count('nick')}")
# # 7.index
# name_tuple = ('nick','jason','tank','sean')
# print(f"name_tuple.index('nick'):{name_tuple.index('nick')}")

# 1.按key取值,可存可取
# dic = {'a':1,'b':2}
# print(f"first dic['a']:{dic['a']}")
# dic['a'] = 3
# print(f"second dic['a]:{dic['a']}")
# # 2.长度len
# dic = {'a':1,'b':2}
# print(f"len(dic):{len(dic)}")
# # 3.in   not in
# dic = {'a':1,'b':2}
# print(f"'a' in dic:{'a' in dic}")
# print(f"l in dic:{1 in dic}")
# # 4.删除
# dic = {'a':1,'b':2}
# del dic['a']
# print(f"dic.get('a'):{dic.get('a')}")
#
# dic = {'a':1,'b':2}
# dic.pop('a')
# print(f"dic.pop('b'):{dic.pop('b')}")
# print(f"dic.get('a'):{dic.get('a')}")
#
# dic = {'a':1,'b':2}
# print(f"dic.popitem():{dic.popitem()}")
# 5.键keys   值values   键值对items
# dic = {'a':1,'b':2}
# print(f"dic.keys():{dic.keys()}")
# print(f"dic.values():{dic.values()}")
# print(f"dic.items():{dic.items()}")
#
# # 6.循环
# dic = {'a':1,'b':2,'c':3,'d':4}
# for k, v in dic.items():
#     print(k,v)
#
# # 1.get
# dic = {'a':1,'b':2}
# print(f"dic.get('a'):{dic.get('a')}")
# print(f"dic.get('c'):{dic.get('c')}")
# # 2.update
# dic1 = {'a':1,'b':2}
# dic2 = {'c':3}
# dic1.update(dic2)
# print(f"dic1:{dic1}")
# 3.formkeys
# dic = dict.fromkeys(['name','age','sex'],None)
# print(f"dic:{dic}")
# # 4.setdefault
# dic = {'a':1,'b':2}
# print(f"dic.setdefault('a'):{dic.setdefault('a',3)}")
# print(f"dic:{dic}")
# print(f"dic.setdefault('c'):{dic.setdefault('c',3)}")
# print(f"dic:{dic}")

一次存多个值

无序

可变

集合类型内置方法

作用:储存一大堆元素的东西,容器数据类型

定义方式:以{}隔开数据 去重,乱序

内置方法:

# 1.长度len
# s = {1,2,'a'}
# print(f"len(s):{len(s)}")
# # 2.in  not in
# s = {1,2,'a'}
# print(f"1 in s:{1 in s}")
# # 3.|并集
# pythoners = {'jason','nick','tank','sean'}
# linuxers = {'nick','egon','kevin'}
# print(f"pythoners|linuxers:{pythoners|linuxers}")
# print(f"pythoners.union(linuxers):{pythoners.union(linuxers)}")
# # 4.&交集
# pythoners = {'jason','nick','tank','sean'}
# linuxers = {'nick','egon','kevin'}
# print(f"pythoners&linuxers:{pythoners&linuxers}")
# print(f"pythoners.intersection(linuxers):{pythoners.intersection(linuxers)}")
# 5.-差集
# pythoners = {'jason','nick','tank','sean'}
# linuxers = {'nick','egon','kevin'}
# print(f"pythoners-linuxers:{pythoners-linuxers}")
# print(f"pythoners.difference(linuxers):{pythoners.difference(linuxers)}")
# # 6.对称差集
# pythoners = {'jason','nick','tank','sean'}
# linuxers = {'nick','egon','kevin'}
# print(f"pythoners^linuxers:{pythoners^linuxers}")
# print(f"pythoners.symmetric_difference(linuxers):{pythoners.symmetric_difference(linuxers)}")
# 7.==
# pythoners = {'jason','nick','tank','sean'}
# linuxers = {'nick','egon','kevin'}
# javers = {'nick','egon','kevin'}
# print(f"pythoners==linuxers:{pythoners==linuxers}")
# print(f"javers==linuxers:{javers==linuxers}")
# # 8.父集
# pythoners = {'jason','nick','tank','seam'}
# linuxers = {'nick','egon','kevin'}
# javaers = {'jason','nick'}
# print(f"pythoners>linuxers:{pythoners>linuxers}")
# print(f"pythoners>=linuxers:{pythoners>=linuxers}")
# print(f"pythoners>=javaers:{pythoners>=javaers}")
# print(f"pythoners.issuperest(javaers):{pythoners.issuperset(javaers)}")
# # 9.子集
# # 1.add
# s = {1,2,'a'}
# s.add(3)
# print(s)
# # 2.remove
# s = {1,2,'a'}
# s.remove(1)
# print(s)
# 3.difference_update
# pythoners = {'jason','nick','tank','sean'}
# linuxers = {'nick','egon','kevin'}
# pythoners.difference_update(linuxers)
# print(f"pythoners,difference_update(linuxers):{pythoners}")
# # 4.discard
# s = {1,2,'a'}
# s.discard(3)
# print(s)
# # 5.isdisjoint
# pythoners = {'jason','nick','tank','sean'}
# linuxers = {'nick','egon','kevin'}
# pythoners.isdisjoint(linuxers)

存多个值

无序

可变

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转载自www.cnblogs.com/jiann/p/11305390.html