Python 数据类型小练习

"""
1. 列表、字符串、元组、字典之间的相互转换
2.列表的遍历方式

"""

print("---------------------第一题---------------------")

str1 = "hello world"
list1 = [11, 22, 33, 44]
list2 = ['aa', 'bb', 'cc', 'dd']
tuple1 = (1, 2, 3, 4)
dict1 = {'name': 'zhangsan', 'age': 18, 'gender': 'boy'}

print('字符串转列表：',list(str1))
print('字符串转列表：',str1.split())

print("元组转列表：",list(tuple1))

print("字典转列表",list(dict1.keys()))
print("字典转列表：",list(dict1.values()))

print("字符串转元组",tuple(str1))
print("列表转元组：",tuple(list1))

print("两个数组合并成一个字典：",dict(zip(list1, list2)))

print("列表转字符串：",''.join(list2))
print("字符串转字典：dict = eval(str)")

print(str(list1))
print(type(str(list1)))


print("---------------------第二题---------------------")

print('方法一')
for i in list2:
    print(i)


print('方法二')
for i in range(0,int(len(list2))):
    print(list2[i])

print('方法三')
i = 0
while i < int(len(list2)):
    print(list2[i])
    i += 1

"""
1. 字符串截取子串
2. 字典的遍历方式
"""

print("---------------------第一题---------------------")
# 字符串截取字串

str1 = 'aaabbbcccdddeeefff'
print('字符串截取子串：',str1[3:9])
print('字符串截取子串：',str1[::3])
print('字符串截取子串：',str1[-1:-7:-1])

print("---------------------第二题---------------------")
# 字典的遍历方式

dict1 = {'name': 'zhangsan', 'age': 18, 'gender': 'boy'}

print('***打印key***')
for i in dict1.keys():
    print(i)

print('***打印value***')
for i in dict1.values():
    print(i)

print('***打印(key,value)***')
for i in dict1.items():
    print(i)

print('***打印key:value***')
for k,v in dict1.items():
    print(k,':',v)

"""
1.列表的增加、删除、更新
2.字典的增加、删除、更新
"""

print("---------------------第一题---------------------")
# 列表的增加、删除、更新
list1 = ['aa', 'bb', 'cc', 'dd']

list1.append(11)
list1.append(22)
list1.append(33)
print('append新增后的列表：',list1)

list1.pop()
print('pop删除后的列表：',list1)

list1.remove(11)
print('remove删除后的列表：',list1)

list1[2] = 'ss'
print('更新后的列表：',list1)


print("---------------------第二题---------------------")
# 字典的增加、删除、更新
dict1 = {'name': 'zhangsan', 'age': 18, 'gender': 'boy'}

dict1['Class'] = 'First'
print('新增后的字典：',dict1)

dict1['age'] = 16
print('更新后的字典：',dict1)

del dict1['name']   # 删除键name
print('del删除后的字典：',dict1)

dict1.clear()    #清空字典
print('clear清空后的字典：',dict1)

"""
1. 列表和元组的区别
2. 访问列表的最后一个元素
"""

print("---------------------第一题---------------------")
# 列表和元祖的区别
list1 = [11, 22, 33, 44, 55]

print("列表：是可变的,内容和长度都可变")
list1[3] = 66
print(list1)
list1.append(77)
print(list1)
"""
打印结果：
列表：是可变的,内容和长度都可变
[11, 22, 33, 66, 55]
[11, 22, 33, 66, 55, 77]
"""
print('********************')

tuple1 = ('aa', 'bb', 'cc', 'dd', 'ee')
tuple2 = (11, 22, 33, 44)
tuple3 = ([111, 222, 333], 'a', 'b')

print("元组：是不可变的")
#tuple1[1] = 22
#print('tuple1')

"""
修改元组内容会报错
Traceback (most recent call last):
  File "C:/2020-04-24.py", line 31, in <module>
    tuple1[1] = 22
TypeError: 'tuple' object does not support item assignment
"""

tuple4 = tuple1 + tuple2
print(tuple4)
# 给元组内的列表新增元素
tuple3[0].append(999)
print(tuple3)


print("---------------------第二题---------------------")
# 访问列表的最后一个元素
list2 = [99, 88, 77, 66]

length = len(list2)-1
print('方法一：',list2[length])

print('方法二：',list2[-1:][0])

list2.reverse()
print('方法三：',list2[0])