Python3-数据结构

列表

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代码实现

List = ['Objective-c','Swift','Python','Java','C++','C']
print('List now content:',List)
print('List length is',len(List))
for item in List:
    print('List content: ',item,end=' \n')

List.append('Ruby')//追加元素

print('List now content:',List)

List.sort()//排序
print('List sort content:',List)

print('List first item:',List[0])

firstItem = List[0]
del List[0]//删除元素
print('firstItem is:',firstItem)
print('List finally is:',List)

运行结果

List now content: ['Objective-c', 'Swift', 'Python', 'Java', 'C++', 'C']
List length is 6
List content: Objective-c
List content: Swift
List content: Python
List content: Java
List content: C++
List content: C
List now content: ['Objective-c', 'Swift', 'Python', 'Java', 'C++', 'C', 'Ruby']
List sort content: ['C', 'C++', 'Java', 'Objective-c', 'Python', 'Ruby', 'Swift']
List first item: C
firstItem is: C
List finally is: ['C++', 'Java', 'Objective-c', 'Python', 'Ruby', 'Swift']

列表是可变的，字符串是不可变的

元组 Tuple

元组是不可变的，不可以编辑或更改元组

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代码实现

mouth = ('day 1','day 2','day 3','day 4','day 5')
print('mouth length is :',len(mouth))

new_mouth = mouth,'day 11','day'
print('new mouth is :',new_mouth)

print('old mouth is :',new_mouth[0])

print('last item of old mouth is :',new_mouth[0][len(mouth)-1])

print('new mouth length is :',len(new_mouth))

运行结果

mouth length is : 5
new mouth is : (('day 1', 'day 2', 'day 3', 'day 4', 'day 5'), 'day 11', 'day')
old mouth is : ('day 1', 'day 2', 'day 3', 'day 4', 'day 5')
last item of old mouth is : day 5
new mouth length is : 3
new mouth actually length is 7

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包含一个元素的元组

mouth = ('day1', )//必须在第一个元素后面加逗号，以便程序区分

字典

键值对，key-value。key 只能是不可变得对象，value 是可变和不可变都可以。

样式：dict = {name:joy,age:18}
示例代码

student = {
    'name' : 'joy',
    'age' : 18,
    'stuNo': '036',
    'birth':'1994-11-24',
}

print('student message is:',student)
print('student name is:',student['name'])

del student['birth']
print('now student message is {}'.format(student))

for name, age in student.items():
    print('name:{} and age :{}'.format(name,age))

student['place'] = 'BeiJing'

if 'place' in student:
    print('now student message is {}'.format(student))

输出结果

student message is: {'name': 'joy', 'age': 18, 'stuNo': '036', 'birth': '1994-11-24'}
student name is: joy
now student message is {'name': 'joy', 'age': 18, 'stuNo': '036'}
name:name and age :joy
name:age and age :18
name:stuNo and age :036
now student message is {'name': 'joy', 'age': 18, 'stuNo': '036', 'place': 'BeiJing'}

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序列

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代码实现

List = ['Objective-c','Swift','Python','Java','C++','C']
new_item = 'single Language'

print('item 0 is:',List[0])
print('item 3 is:',List[3])
print('item -2 is:',List[-2])
print('item -1 is:',List[-1])
print('new_item is:',new_item[7])
print('===========================')
# 列表截取
print('item 1-3:',List[1:3])
print('item 2-end is:',List[2:])
print('item 1to-1 is:',List[1:-1])
print('item 0-end is:',List[:])
# 字符串截取
print('new_item 7-end is:',new_item[7:])
print('item 0-4:',new_item[0:4])
print('item 4to-4:',new_item[4:-4])

输出结果

item 0 is: Objective-c
item 3 is: Java
item -2 is: C++
item -1 is: C
new_item is: L
===========================
item 1-3: ['Swift', 'Python']
item 2-end is: ['Python', 'Java', 'C++', 'C']
item 1to-1 is: ['Swift', 'Python', 'Java', 'C++']
item 0-end is: ['Objective-c', 'Swift', 'Python', 'Java', 'C++', 'C']
new_item 7-end is: Language
item 0-4: sing
item 4to-4: le Lang

使用索引获取序列中各个项目，“[ ]”中指定序列的制定数组，Python 将返回该序列制定位置的项目，Python计数从0开始。索引计数也可以为负数，负数表示从序列的末尾向首位开始计数。

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还可以设置截取跨度长度

List[ : : 2]//表示从起始-结尾 截取长度为2的项目

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集合

代码实现

stu = set(['jone','tom','jerry','jack'])
print('stu:',stu)
print('jack is in stu? ','jack' in stu)
print('lee is in stu? ','lee' in stu)
stus = stu.copy()
stus.add('jodan')
print('stus:',stus)
print('stus is stu superset? ',stus.issuperset(stu))
print('stus and stu all item? ',stu | stus)
stus.remove('tom')
stus.add('robert')
print('stu:',stu)
print('stus:',stus)

print('stus and stu all item? ',stu | stus)
print('stus and stu intersection item? ',stu & stus)

输出结果

stu: {'jack', 'tom', 'jerry', 'jone'}
jack is in stu? True
lee is in stu? False
stus: {'tom', 'jack', 'jerry', 'jodan', 'jone'}
stus is stu superset? True
stus and stu all item? {'tom', 'jack', 'jerry', 'jodan', 'jone'}
stu: {'jack', 'tom', 'jerry', 'jone'}
stus: {'jack', 'robert', 'jerry', 'jodan', 'jone'}
stus and stu all item? {'tom', 'jack', 'robert', 'jerry', 'jodan', 'jone'}
stus and stu intersection item? {'jack', 'jerry', 'jone'}

set 支持拷贝、增加、删除等基本操作。

引用

创建一个对象，分配给该对象某个变量，变量只会 refer 某个对象，不会代表对象本身。变量名只是指向计算机内存储该对象的内存地址。在引用时候会出现不同的效果。
案例

List = ['Objective-c','Swift','Python','Java','C++','C']
new_list = List
# new_list 只是指向 List 地址的名称，List 改变，new_list也会随之改变
List.remove("C")
print('List:',List)
print('newList:',new_list)
# new_list 与 List 指向同一对象

copy_list = List[:]
# 通过切片 复制出一份 List 的副本
print('copy_list:',copy_list)
del copy_list[0]

print('List:',List)
print('newList:',new_list)
print('copy_list:',copy_list)

输出结果

List: ['Objective-c', 'Swift', 'Python', 'Java', 'C++']
newList: ['Objective-c', 'Swift', 'Python', 'Java', 'C++']
copy_list: ['Objective-c', 'Swift', 'Python', 'Java', 'C++']
List: ['Objective-c', 'Swift', 'Python', 'Java', 'C++']
newList: ['Objective-c', 'Swift', 'Python', 'Java', 'C++']
copy_list: ['Swift', 'Python', 'Java', 'C++']

如果想操作而又不影响源数据的情况下，使用 “ List[ : ] ” 这样得到的序列是拷贝出一份副本，互相操作不会影响；如果采用 “ a=b ”，则操作会造成联动，慎用！

字符串补充

代码实现

List = ['Objective-c','Swift','Python','Java','C++','C']
str = 'python'
if str.startswith('py'):
    # 字符串以什么开头
    print('str start at \'py\'')
if 'on' in str:
    # 字符串包含
    print('str contain \'on\'')

if str.find('th') != -1:
    # 查找字符串的位置，如果找不到则返回"-1"
    print('\'th\' in str location is:',str.find('th'))

otherStr = ' ~ '
print('List change str is:',otherStr.join(List))
#otherStr 是作为List 中每个项目的分隔符，返回一个更大的字符串

输出结果

str start at 'py'
str contain 'on'
'th' in str location is: 2
List change str is: Objective-c ~ Swift ~ Python ~ Java ~ C++ ~ C