Two parts:
1. Single Value
digital
Integer: int
Long integer: long
Float: float, double
Plural: do not need
A Boolean value: True, false
1 0
String str
2. collection
List "======" array list in other languages ()
Tuple tuple ()
Dictionary dict {}
Hash table
String formatting:
% S string
% D Integer
% F float
The first:
name = "I am %s,age %d"
name = "I am %s,age %d" % ("alex",60)《======================》name % ("steven",60)
The second (more efficient):
name = "I am {0},age {1}"
name.format("steven",60)
Index and slice:
name = "abcdefg"
name[0] = "a"
name[0:2] = "ab"
name[:] = "abcdefg"
as (name) = 7
name[-1] = name[len(name)-1] ="g"
Remove trailing spaces:
name = " abcd "
name.strip()
Remove only left a space:
name.lstrip()
Only remove the right space:
name.rstrip()
Split:
name = "rooney,linda,ramos"
name.split(',')
[ 'Rooney', 'beautiful', 'branches']
List
Create a list:
name_list = ["alex","tom,","rooney","linda"]
或
name_list = list(["alex","tom,","rooney","linda"])
添加元素：
name_list.append('steven') 默认添加到最后
删除元素：
del name_list[0] 删除name_list列表的第0个元素
长度：
len(name_list)
列表转换成字符串：
>>> name_list
['linda', 'ramos', 'pique']
>>> "_".join(name_list)--------->以“_”组合列表转换成字符串
'linda_ramos_pique'
包含：
>>> name_list
['linda', 'ramos', 'pique']
>>> "rooney" in name_list -------->rooney在不在name_list列表里
False
元组：
创建元组：
ages = (11,22,33,44,55)
或
ages = tuple((11,22,33,44,55))
比较str，list，tuple
共同点：
索引，切片，长度，包含，循环
不同点：
str
修改后，重新开辟内存地址空间
list
修改后，内存地址空间不变
tuple
不可修改
字典：键值对
字典无序
特殊的for循环
key()---->列表
values()---->列表
items()----->仅for循环时使用，将元素赋值给k，v
创建字典：
person = {"name":"rooney","age":32}
字典的查找：
person["name"] name对应的value
person.keys() 所有key
person.values() 所有value
person.items() 所有元素
for k,v in person.items():
print (k,v)
print('==========')