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其他 2019-08-05 17:48:00 阅读次数: 0

python进阶

一、列表类型的内置方法

1.1 用途

​ 用来描述多个装备，多个爱好，多种课程等。

1.2 定义

​ []内可以有多个任意类型的值，使用逗号进行分割。

name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(F"{name_list[1]}")

xiaofu

1.3 常用操作+内置方法

1.3.1 优先掌握

  1. 按索引取值（正相+反向），即可存也可取

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(F"{name_list[-1]}")

daxiong

  2. 切片

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(F"{name_list[0:3:2]}")

['panghu', 'jingxiang']

  3. 长度

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(F"{len(name_list)}")

4

  4. 成员运算in和not in

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(F"{'daxiong' in name_list}")
print(F"{'pangmei' in name_list}")

True
False

  5. 追加值

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
name_list.append('xiaodingdang')
print(F"{name_list}")

['panghu', 'xiaofu', 'jingxiang', 'daxiong', 'xiaodingdang']

  6. 删除

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
del name_list[3]
print(F"{name_list}")

['panghu', 'xiaofu', 'jingxiang']

  7. 循环

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
for name in name_list:
    print(name)

panghu
xiaofu
jingxiang
daxiong

1.3.2 需要掌握

  1. insert()

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
name_list.insert(3,'xiaodingdang')
print(f'{name_list}')

['panghu', 'xiaofu', 'jingxiang', 'xiaodingdang', 'daxiong']

  2. pop()(默认删除最后一个元素)

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(f'{name_list.pop(2)}')
print(f'{name_list}')

jingxiang
['panghu', 'xiaofu', 'daxiong']

  3. remove()

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{name_list.remove('xiaofu')}")
print(f'{name_list}')

None
['panghu', 'jingxiang', 'daxiong']

  4. count()

    name_list = ['panghu','xiaofu','xiaofu','jingxiang','daxiong']
print(f"{name_list.count('xiaofu')}")

2

  5. index()(引索)

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{name_list.index('xiaofu')}")

1

  6. clear()

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
name_list.clear()
print(f"{name_list}")

[]

  7. copy()

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{name_list.copy()}")

['panghu', 'xiaofu', 'jingxiang', 'daxiong']

  8. extend

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
name_list2 = ['xiaodingdang']
name_list.extend(name_list2)
print(f"{name_list}")

['panghu', 'xiaofu', 'jingxiang', 'daxiong', 'xiaodingdang']

  9. reverse()(倒叙)

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
name_list.reverse()
print(f"{name_list}")

['daxiong', 'jingxiang', 'xiaofu', 'panghu']

  10. sort

    name_list = ['panghu','xiaofu','jingxiang','daxiong']
name_list.sort()
print(f"{name_list}")

['daxiong', 'jingxiang', 'panghu', 'xiaofu']

1.4 存值

​ 存多个值

1.5有序性

​ 有序

1.6 可变性

​ 可变

二、元组类型的内置方法

​ 元组是不可变的列表，即元组的值不可更改，因此元组一般只用于只存不取的需求。也因此元组可以被列表取代掉，所以元组相比较列表使用的很少。元组相比较列表的优点为：列表的值修改后，列表的结构将会发生改变，而元组只需要存储，因此列表在某种程度上而言需要占用更多的内存。但是目前工业上内存已经不是问题了，所以工业上元组一般不会使用。

2.1 用途

​ 多个装备、多个爱好、多门课程。

2.2 定义

​ 在()内可以有多个任意类型的值，逗号分隔元素。

2.3 常用操作+内置方法

  1. 索引取值

    name_tuple = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{name_tuple}")

['panghu', 'xiaofu', 'jingxiang', 'daxiong']

  2. 切片(顾头不顾尾，步长)

    name_tuple = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{name_tuple[1:3:2]}")

xiaofu

  3. 长度

    name_tuple = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{len(name_tuple)}")

4

  4. 成员运算

    name_tuple = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{'daxiong' in name_tuple}")

True

  5. 循环

    name_tuple = ['panghu','xiaofu','jingxiang','daxiong']
for name in name_tuple:
    print(name)

panghu
xiaofu
jingxiang
daxiong

  6. count()

    name_tuple = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{name_tuple.count('daxiong')}")

1

  7. index()

    name_tuple = ['panghu','xiaofu','jingxiang','daxiong']
print(f"{name_tuple.index('daxiong')}")

3

2.4 存值

​ 多个值

2.5 有序性

​ 有序

2.6 可变性

​ 不可变数据类型

三、字典类型的内置方法

3.1 用途

​ 存多个值，但每一个值都有一个key与之对应，key对值有描述功能。多用于存的值表示的是不同的状态时，例如存的值有姓名、年龄、身高、体重、爱好。

3.2 定义

​ {}内用逗号分隔开多个元素，每一个元素都是key：value的形式，value可以是任意数据类型，而key通常应该是字符串类型，但是key必须为不可变类型。

dic = {'a': 1, 'b': 2}  # dic = dict({'a':1,'b':2})
print(f"dic: {dic}")

dic: {'a': 1, 'b': 2}


dic = dict(a=1, b=2, c=3)
print(f"dic: {dic}")

dic: {'a': 1, 'b': 2, 'c': 3}


dic = {1: 'a', 0: 'b'}
print(f"dic[0]: {dic[0]}") 

dic[0]: b

3.3 常用操作+内置方法

3.3.1 重点

  1. 按key存取值：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']}")

first dic['a']: 1
second dic['a']: 3
  1. 长度len
dic = {'a': 1, 'b': 2}
print(f"len(dic): {len(dic)}")

len(dic): 2
  1. 成员运算in和not in
dic = {'a': 1, 'b': 2}
print(f"'a' in dic: {'a' in dic}")
print(f"1 in dic: {1 in dic}")

'a' in dic: True
1 in dic: False
  1. 删除
dic = {'a': 1, 'b': 2}
del dic['a']
print(f"dic.get('a'): {dic.get('a')}")

dic.get('a'): None


dic = {'a': 1, 'b': 2}
dic.pop('a')  # 指定元素删除
print(f"dic.pop('b'): {dic.pop('b')}")
print(f"dic.get('a'): {dic.get('a')}")

dic.pop('b'): 2
dic.get('a'): None


dic = {'a': 1, 'b': 2}
print(f"dic.popitem(): {dic.popitem()}")  # popitem() 方法随机返回并删除字典中的一对键和值(一般删除末尾对)。

dic.popitem(): ('b', 2)
  1. 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()}")

dic.keys(): dict_keys(['a', 'b'])
dic.values(): dict_values([1, 2])
dic.items(): dict_items([('a', 1), ('b', 2)])
  1. 循环
dic = {'a': 1, 'b': 2, 'c': 3, 'd': 4}
for k, v in dic.items():  
    print(k, v)
    
a 1
b 2
c 3
d 4

3.3.2 需要掌握

  1. get()
dic = {'a': 1, 'b': 2}
print(f"dic.get('a'): {dic.get('a')}")
print(f"dic.get('c'): {dic.get('c')}")

dic.get('a'): 1
dic.get('c'): None
  1. update()
dic1 = {'a': 1, 'b': 2}
dic2 = {'c': 3}
dic1.update(dic2)
print(f"dic1: {dic1}")

dic1: {'a': 1, 'b': 2, 'c': 3}
  1. fromkeys()
dic = dict.fromkeys(['name', 'age', 'sex'], None)
print(f"dic: {dic}")

dic: {'name': None, 'age': None, 'sex': None}
  1. 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}")

dic.setdefault('a'): 1
dic: {'a': 1, 'b': 2}
dic.setdefault('c'): 3
dic: {'a': 1, 'b': 2, 'c': 3}

四、集合类型的内置方法

4.1 用途

​ 用于关系运算的集合体，由于集合内的元素无序且集合元素不可重复，因此集合可以去重，但是去重后的集合会打乱原来元素的顺序。

4.2 定义

​ {}内用逗号分隔开多个元素，每个元素必须是不可变类型。

s = {1, 2, 1, 'a'}  
print(f"s: {s}")

s: {1, 2, 'a'}


s = {1, 2, 1, 'a', 'c'}
for i in s:
    print(i)
1
2
c
a


s = set('hello')
print(f"s: {s}")

s: {'e', 'o', 'h', 'l'}

4.3 常用操作和内置方法

4.3.1 重点

1.长度len

s = {1, 2, 'a'}
print(f"len(s): {len(s)}")

len(s): 3

2.成员运算in和not in

s = {1, 2, 'a'}
print(f"1 in s: {1 in s}")

1 in s: True

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)}")

pythoners|linuxers: {'egon', 'tank', 'kevin', 'jason', 'nick', 'sean'}
pythoners.union(linuxers): {'egon', 'tank', 'kevin', 'jason', 'nick', 'sean'}

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)}")

pythoners&linuxers: {'nick'}
pythoners.intersection(linuxers): {'nick'}

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)}")

pythoners-linuxers: {'tank', 'jason', 'sean'}
pythoners.difference(linuxers): {'tank', 'jason', 'sean'}

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)}")

pythoners^linuxers: {'egon', 'tank', 'kevin', 'jason', 'sean'}
pythoners.symmetric_difference(linuxers): {'egon', 'tank', 'kevin', 'jason', 'sean'}

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}")

pythoners==linuxers: False
javers==linuxers: True

8.父集：>、>=

pythoners = {'jason', 'nick', 'tank', 'sean'}
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.issuperset(javaers): {pythoners.issuperset(javaers)}")

pythoners>linuxers: False
pythoners>=linuxers: False
pythoners>=javaers: True
pythoners.issuperset(javaers): True

9.子集：<、<=

pythoners = {'jason', 'nick', 'tank', 'sean'}
linuxers = {'nick', 'egon', 'kevin'}
javaers = {'jason', 'nick'}
print(f"pythoners<linuxers: {pythoners<linuxers}")
print(f"pythoners<=linuxers: {pythoners<=linuxers}")
print(f"javaers.issubset(javaers): {javaers.issubset(javaers)}")

pythoners<linuxers: False
pythoners<=linuxers: False
javaers.issubset(javaers): True

4.3.2 掌握

1.add()

s = {1, 2, 'a'}
s.add(3)

print(s)
{1, 2, 3, 'a'}

2.remove()

s = {1, 2, 'a'}
s.remove(1)

print(s)
{2, 'a'}

3.difference_update()

pythoners = {'jason', 'nick', 'tank', 'sean'}
linuxers = {'nick', 'egon', 'kevin'}
pythoners.difference_update(linuxers)

print(f"pythoners.difference_update(linuxers): {pythoners}")
pythoners.difference_update(linuxers): {'tank', 'jason', 'sean'}

4.discard()

s = {1, 2, 'a'}
s.discard(3)

print(s)
{1, 2, 'a'}

5.isdisjoint()

# set之isdisjoint()，集合没有共同的部分返回True，否则返回False
pythoners = {'jason', 'nick', 'tank', 'sean'}
linuxers = {'nick', 'egon', 'kevin'}
pythoners.isdisjoint(linuxers)

print(f"pythoners.isdisjoint(linuxers): {pythoners.isdisjoint(linuxers)}")
pythoners.isdisjoint(linuxers): False

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