数值运算
print(2+2)
1+1
//4
//2
4*5
//20
10/3
//3.3333333
10%3
//1
tang=3
tang
//3
type(tang)
//int
tang=1.5
//float
类型转换
int(tang)
//1
tang2=int(tang)
type(tang2)
//int
type(float(tang2))
//float
tang2
//1
tang_str='123'
type(tang_str)
//str
int(tang_str)
//123
str(123)
//'123'
基本数值操作
abs(15.6)
//15.6
round(15.6)
//16
round(15.4)
//15
min(2,3,4,5)
//2
max(2,3,4,5)
//5
1.3e5
//130000.0
1.3e-5
//1.3e-05
0xFF
//255
字符串
tang_str='hello python'
print(tang_str)
//hello python
tang='hello'+'python'
tang
//'hellopython'
tang_str*3
//'hello pythonhello pythonhello python'
len(tang)
//11
字符串操作
tang='1 2 3 4 5'
tang.split()
//['1','2','3','4','5']
tang='1,2,3,4,5'
tang=tang.split(',')
tang
//['1','2','3','4','5']
tang_str=' '
tang_str.join(tang)
//'1 2 3 4 5'
tang='hello python'
tang.replace('python','world')
//'hello world'
tang
//hello python
tang='hello python'
tang2=tang.replace('python','world')
//'hello world'
tang2.upper()
//'HELLO WORLD'
tang2='HELLO WORLD'
tang2.lower()
//'hello world'
tang=' hello python '
tang.strip()
//'hello python'
tang.lstrip()#去掉左边的空格
//‘hello python '
tang.rstrip()
//' hello python'
' {} {} {}'.format('tang','yu','di')
//'tang yu di'
'{2} {1} {0}'.format('tang','yu','di')
//'di yu tang'
'{tang} {yu} {di}'.format(tang=10,yu=5,di=1)
//'10 5 1'
tang='tang yu di:'
a=123
b=456
c=789
result='%s %f %d'%(tang,b,c)
result
//'tang yu di:456.000000 789'
tang_str='hello python'
print(tang_str)
//hello python
tang='hello'+'python'
tang
//'hellopython'
tang_str*3
//‘hello pythonhello pythonhello python’
len(tang)
//11
字符串操作
tang='1 2 3 4 5'
tang.split()
//['1','2','3','4','5']
tang='1,2,3,4,5'
tang.split(',')
//['1','2','3','4','5']
tang='1,2,3,4,5'
tang.split(',')
tang
//['1','2','3','4','5']
tang_str=' '
tang_str.join(tang)
//'1 2 3 4 5'
tang='hello python'
tang.replace('python','world')
列表
tang=[]
type(tang)
//list
tang=[1,2,3,4]
tang
//[1,2,3,4]
tang=['1','2','3','4']
tang
//['1','2','3','4']
tang=[1,'tangyudi',3.5]
yang
[1,'tangyudi',3.5]
//通过【】来创建一个list没有长度限制，可以存放任何内容
tang=list([1,2,3])
tang
//[1,2,3]
a=[123,456]
b=['tang','yudi']
a+b
//[123,456,'tang','yudi']
type(a+b)
//list
a*2
//[123,456,123,456]
a[0]=789
a
//[789,456]
a[:]=['tang','yudi']
a
//['tang','yudi']
a=[1,2,3,4,5,6,7,8,9]
a[4:7]
//[5,6,7]
def a[0]
[2,3,4,5,6,7,8,9]
def a[3:]
a
//[2,3,4]
a[1,2,3,4,,5,6,7,8,9]
8 in a
/True
10 in a
//False
tang='tang yu di'
'tang' in tang
//True
a=[1,2,[3,4]]
a
//[1,2,[3,4]]
a[2]
//[3,4]
a[2][1]
//4
tang=['apple','banana','apple','apple','apple','banana','banana]
tang.count('banana')
//3
tang=['apple','1','2','3','4','5','6']
tang.index('2')
//2
列表添加
tang=[]
tang.append('tang')
tang
//['tang','tang','tang']
tang.append(['tang,'yudi'])
tang
//['tang','tang','tang',['tang,'yudi'],'tang',]
tang.insert(2,'python')
tang
//['tang','tang','python','tang',['tang,'yudi'],'tang','tang']
tang.remove(['tang,'yudi'])
tang
//['tang','tang','python','tang','tang','tang']`
tang.remobe('tang')
tang
//['tang','python','tang','tang','tang']``
tang.remobe('tang')
tang
['python','tang','tang','tang']``//只去掉第一个每次
tang.pop(1)
'tang'
tang
//['python','tang','tang']
tang=[1,2,3,9,6,3,2]
tang.sort()
tang
//[1,2,2,3,3,6,9]
tang=[1,2,3,9,6,3,2]
tang2=sorted(tang)
tang2
//[1,2,2,3,3,6,9]
tang
//[1,2,3,9,6,3,2]
tang=['di,'yu','tang']
tang.reverse()
tang
//['tang','yu','di']
字典结构
tang={}
type(tang)
//dict
tang=dict()
type(tang)
//dict
字典的结构操作
key-value
tang[’ first’]=‘123’
tang
//[‘first’:123]
tang[‘python’]=456
tang
//[‘first’:123,‘python’:456]
tang[‘python’]
//456
tang[‘python’]=789
tang
//{‘first’:123,‘python’:789}
tang={‘tang’:123,‘yu’:456,‘di’:789}
tang
//{‘di’:789,‘tang’:123,‘yu’:456}
tang
//
tang_value={1,2,3}
tang={}
tang[‘yudi’]=tang_value
tang[‘yudi2’]=3
tang[‘yudi2’]=‘4’
tang
//{‘yudi’:[1,2,3],‘yudi2’:‘4’}
tang={}
d1={‘tang’:123.‘yudi’:456}
d2={‘tang2’:456,‘yudi2’:789}
tang[‘test1’]=d1
tang[‘test2’]=d2
//{‘test1’:{‘tang’:123,‘yudi’:456},‘test2’:{‘tang2’:456,‘yudi2’:789}
tang=dict([(‘tang’,123),(‘yudi’,456)])
tang
//{‘tang’:123,‘yudi’:456}
tang[‘tang’]+=1
tang
//{‘tang’:124,‘yudi’:456}
tang.get(‘tang’)
125
tang[‘tang’]
//125
tang.get(‘fengzi’,‘meiyou’)
//‘mriyou’
tang
//{‘tang’:125,‘yudi’:456}
tang.pop(‘tang’)
//125
tang
//{‘yudi’:456}
del tang[‘yudi’]
tang
//{}
tang={‘tang’:123,‘yudi’:456}
tang2={‘tang’:789,‘python’:888}
tang.update(tang2)
//{‘python’:888,‘tang’:789,‘yudi’:456}
‘tang’ in tang
//True
‘hello’ in tang
//False
tang.keys()
//dict_keys([‘tang’,‘python’,‘yudi’])
tang.values()
//dict_values([789,888,456])
tang.items()
//dict_items([(‘tang’,789),(‘python’,888),(‘yudi’.456)])