python 基础数据类型汇总

数据类型小结(各数据类型常用操作)

一.数字/整型int

int()强行转化数字

二.bool类型False&True

bool()强行转化布尔类型.
0,None,及各个空的字符类型为False.其余均为Ture.

三.字符串str

str()强行转化字符串

#列表转化字符换
nums = [11,22,33,44]
for a in range(0,len(nums)):
    nums[a] = str(nums[a]) 
result = \'\'.join(nums)
print(result)

.upper()转化大写

name = \'abc\'
new_name = name.upper()
print(new_name)

.lower()转化小写

name = \'ABC\'
new_name = name.lower()
print(new_name)

.replace()替换

message = input(\'请输入"大傻逼"\')
new_mes = message.replace(\'傻逼\',\'**\')
print(new_mes)
#.replace(\'原字符\',\'替换字符\',\'替换个数\')

.strip()去首尾空格

name = \' abc \'
new_name = name.strip()
print(new_name)
#.rstrip()去除右侧空格   .lstrip()去除左侧空格

.split()分割

name = \'abcdefg\'
new_name = name.split(\'d\')
print(new_name)
#.split(\'分割点\',分割次数)

.isdecimal()判断是否可以转化位数字

while True:
    num = input(\'请输入内容:\')      
    num1= num.isdigit()             #print(num1) 数字的话输出True,非数字输出FALSE            
    if num1:
        print(\'你输入正确\')
        break
    else:
        print(\'请输入数字\')

.startswith() 判断是否以()开头,输出值为bool类型
```
name = \'bigox\'
print(name.startswith(\'big\'))
```
endswith() 判断是否以()结尾,输出值为bool类型同.startswith()用法相同

.format()格式(同字符串格式化)

name = \'我叫:{0},年龄:{1}\'.format(\'bigox\',24)
print(name)

.encode() :编码转换

name  = \'刘\'              #解释器读取到内存后,按照unicode编码存储:8字节.
print(name.encode(\'utf-8\'))    #转化为utf-8编码

.join()循环每个元素,并在元素之间加入连接符.

name = \'bigox\'
new_name = \'_\'.join(name)
print(new_name)       #输出结果为  b_i_g_o_x

四.列表list

列表转换list()

#列表转化字符换
nums = [11,22,33,44]
for a in range(0,len(nums)):
    nums[a] = str(nums[a]) 
result = \'\'.join(nums)
print(result)

.pop(索引)

a = li.pop(2) #在列表中删除,并将删除的此数据赋值给a
```
name = [\'bigox\',\'xo\',\'ox\']
name.pop(1)
print(name)
```

del 列表 [索引]

name = [\'bigox\',\'xo\',\'ox\']
del name[0:2]
print(name)

.append()列表最后追加元素

lst = ["麻花藤", "林俊杰", "周润发", "周芷若"] 
print(lst) 
lst.append("wusir") 
print(lst)

.insert()在指定的索引位置插入元素

lst = ["麻花藤", "林俊杰", "周润发", "周芷若"] 
print(lst) 
lst.insert(1,"wusir") 
print(lst)

remove()**指定元素删除

name = [\'bigox\',\'xo\',\'ox\']
name.remove(xo)
print(name)

.clear()**清空

.extend**()添加

li = ["alex", "WuSir", "ritian", "barry", "wenzhou"]
s = \'qwert\'
li.extend(s)
print(li)
#---------------------------
lst = ["王志文", "张一山", "苦海无涯"]
lst.extend(["麻花藤", "麻花不疼"])
print(lst)

.reverse()反转

v = [1,2,3,4,5,6]
v.reverse()
print() #[6, 5, 4, 3, 2, 1]

.sort排序

v = [1,3,7,4,5,6]
v.sort()
print() 	#[1, 3, 4, 5, 6, 7]
#v.sort()	从小到大排序(默认)
#v.sort(reverse=True)  从大到小排序

五.元组tuple

强制转换：

tuple(\'adfadfasdfasdfasdfafd\')

v1 = tuple(\'adfadfasdfasdfasdfafd\')
print(v1) # (\'a\', \'d\', \'f\', \'a\', \'d\', \'f\', \'a\', \'s\', \'d\', \'f\', \'a\', \'s\', \'d\', \'f\', \'a\', \'s\', \'d\', \'f\', \'a\', \'f\', \'d\')

tuple([11,22,33,44])

v1 = tuple([11,22,33,44])
print(v1)  # (11, 22, 33, 44)

元组子元素不可变,而子元素内部的子元素是可以变的,取决于元素是否为可变对象
元组中如果只有一个元素,一定要添加一个逗号,否者不是元组

六.字典dict

字典键的数据类型不能为list和tuple,值可以为任何类型.
.keys()取键
```
for i in info.keys():
	print(i)
```
.values()取值
```
for i in info.values():
	print(i)
```
.items()取键值对
```
for i in info.items():
	print(i)
```

.get()以键取值,如果键不存在返回原定结果

info = {\'k1\':\'v1\',\'k2\':\'v2\'}
a = info.get(\'k1\')
print(a)	#v1
info2 = [\'11111\']
b = info.get(\'11111\',22222)
print(b)	#22222

.update()更新_存在覆盖更新,不存在添加

info = {\'k1\':\'v1\',\'k2\':\'v2\'}
info.update({\'k1\':\'v0\',\'k3\':\'v3\'})
print(info)	#{\'k1\': \'v0\', \'k2\': \'v2\', \'k3\': \'v3\'}

七.集合set

无序,不可重复
在集合中True与数字1重复,False与数字0重复

.add() 添加

info = {\'k1\',\'k2\'}
info.add(\'k3\')
print(info)

.discard()删除

info = {\'k1\',\'k2\',\'k3\'}
info.discard(\'k3\')
print(info)

要修改,需要先删除再添加
.clear()清空

.update()

info = {\'k1\',\'k2\'}
info.update({\'k1\',\'k3\',\'v3\'})
print(info)	#{\'k1\',\'k2\',\'k3\',\'v3\'}

.intersection() 交集

命令后的 () 可以是集合,也可以是列表.
```
info = {1,2,3}
print(info.intersection({1,3,4}))	#{1,3}
```

.union()并集

info = {1,2,3}
print(info.union({1,3,4}))	#{1,2,3,4}

.difference()差集

info = {1,2,3}
print(info.union({1,3,4}))	#{2,4}