python基础-列表、元组、range、列表字符串转换

列表增删改查

list = [1,"a",True,(1,2,3),{"a":"1"}]#遍历for i in list:    print(i)#判断1是不是在list中if 1 in list:    print("----")"""增"""list.append("a")print(list)list.insert(0,"ba")print(list)#迭代插入list.extend("cc")print(list)list.extend([1,"111"])print(list)"""删除"""#按着索引去删除--有返回值，返回被删掉的元素list.pop(0)print(list)#倒序删除list.pop(-2)print(list)#按着元素删除list.remove("a")print(list)#del按着索引删除del list[0]print(list)#del删除切片可以有步长del list[0:4:2]print(list)"""修改"""list[0] = "nnn"print(list)#先删除，然后切片迭代修改添加  迭代list[0:3] = "切片修改"print(list)#迭代添加list[0:3] = ["asd","sss","ddd","er"]print(list)"""查询""""""跟字符串的切片方法一摸一样"""#集合倒序打印print(list[-1])#集合切片(是列表)--字符串切片是字符串print(list[0::2])print(list[-1::-2])print(list)#循环查询for a in list:    print(a)"""删除整个列表"""list.clear()print(list)del listprint(list)

输出如下：

E:\python\python_sdk\python.exe E:/python/py_pro/safly.py1aTrue(1, 2, 3){'a': '1'}----[1, 'a', True, (1, 2, 3), {'a': '1'}, 'a']['ba', 1, 'a', True, (1, 2, 3), {'a': '1'}, 'a']['ba', 1, 'a', True, (1, 2, 3), {'a': '1'}, 'a', 'c', 'c']['ba', 1, 'a', True, (1, 2, 3), {'a': '1'}, 'a', 'c', 'c', 1, '111'][1, 'a', True, (1, 2, 3), {'a': '1'}, 'a', 'c', 'c', 1, '111'][1, 'a', True, (1, 2, 3), {'a': '1'}, 'a', 'c', 'c', '111'][1, True, (1, 2, 3), {'a': '1'}, 'a', 'c', 'c', '111'][True, (1, 2, 3), {'a': '1'}, 'a', 'c', 'c', '111'][(1, 2, 3), 'a', 'c', 'c', '111']['nnn', 'a', 'c', 'c', '111']['切', '片', '修', '改', 'c', '111']['asd', 'sss', 'ddd', 'er', '改', 'c', '111']111['asd', 'ddd', '改', '111']['111', '改', 'ddd', 'asd']['asd', 'sss', 'ddd', 'er', '改', 'c', '111']asdsssddder改c111[]<class 'list'>Process finished with exit code 0

排序，反转

list = [1,"acb",True,(1,2,3,"acb"),{"a":"1"}]count = list.count("acb")print(count)#正序排序num = [-9,2,3,7,1,9,6,-2]num.sort()print(num)#倒叙排序num.sort(reverse=True)print(num)#反转num.reverse()print(num)#查找某个元素的索引print(list.index(1))

输出如下：

E:\python\python_sdk\python.exe E:/python/py_pro/safly.py1[-9, -2, 1, 2, 3, 6, 7, 9][9, 7, 6, 3, 2, 1, -2, -9][-9, -2, 1, 2, 3, 6, 7, 9]0Process finished with exit code 0

元组

list = (1,"acbdgg",True,(1,2,3,"acb"),{"a":"1"},[1,2,"sss"])#只有查询方法，按着索引print(list[1][2:4])#切片出来也是元组print(list[1:4])#遍历for i in list:    print(i)#孙子可以修改,但是list[3]是元组，不能修改，list[5]可以修改list[5][2] = "aaaaa"print(list)

输出如下：

E:\python\python_sdk\python.exe E:/python/py_pro/safly.pybd('acbdgg', True, (1, 2, 3, 'acb'))1acbdggTrue(1, 2, 3, 'acb'){'a': '1'}[1, 2, 'sss'](1, 'acbdgg', True, (1, 2, 3, 'acb'), {'a': '1'}, [1, 2, 'aaaaa'])Process finished with exit code 0

range

#range先当于可迭代对象for i in range(1,10,2):    print(i)print("-----------")#含头不含尾，步长为1for i in range(1, 10):    print(i)print("-----------")for i in range(10,1,-2):    print(i)print("========嵌套循环输出所有的信息========")li = [1,2,3,4,[1,2,"太白","alex"],2]for i in range(0,len(li)):    if i == 4:        for j in li[i]:            print(j)    else:        print(li[i])

输出如下：

E:\python\python_sdk\python.exe E:/python/py_pro/safly.py13579-----------123456789-----------108642=================123412太白alex2Process finished with exit code 0

range切片

# print(3>2>2)l = range(10)s = l[0:2]for i in s:    print(i)print(l[-2])

输出如下：

018

练习题

5)通过对li列表的切片形成新的列表l5,l5 = [‘c’]
li = [1,3,2,’a’,4,’b’,5,’c’]

li = [1,3,2,'a',4,'b',5,'c']#正正print(li[len(li)-1::])print(li[len(li)-1:len(li)-2:-1])print(li[-1::1])print(li[-1:-2:-1])如下：

输出如下：

['c']['c']['c']['c']

列表拼接

str1 = ["123","add"]str2 = ["ee","gb",True]#通过+方式进行列表的添加newStr = str1 + str2print(newStr)#append添加newStr.append("bgg")print(newStr)#extend添加newStr.extend("nnn")print(newStr)#extend迭代添加newStr.extend(["gjf","dert4"])print(newStr)#以下的方式不行# newStr.append("fsf","af")# print(newStr)

输出如下：

['123', 'add', 'ee', 'gb', True]['123', 'add', 'ee', 'gb', True, 'bgg']['123', 'add', 'ee', 'gb', True, 'bgg', 'n', 'n', 'n']['123', 'add', 'ee', 'gb', True, 'bgg', 'n', 'n', 'n', 'gjf', 'dert4']

列表字符串转换

print("-------将str以*相连----")s = "alex"temp = "*".join(s)print(temp)print("-------list转str----")listTemp = ["ad","gg","ee"]temp = "".join(listTemp)print(temp)print("-------list转str str()----")lis = str([2,3,'k'])print(lis,type(lis))for i in lis:    print(i)lis = lis.replace('k','100')print(lis)print("------将str ---> list   split-----")s="wefjjlajoij"temp = s.split("a")print(temp)print("------将str ---> list   list-----")s = "abd"aaa = list(s)print(aaa)

输出如下：

E:\python\python_sdk\python.exe E:/python/py_pro/safly.py-------将str以*相连----a*l*e*x-------list转str----adggee-------list转str str()----[2, 3, 'k'] <class 'str'>[2,3,'k'][2, 3, '100']------将str ---> list   split-----['wefjjl', 'joij']------将str ---> list   list-----['a', 'b', 'd']