python中常用的九个语法技巧_python

a=10000000000

#数字分隔符
a0=10000000000
a1=100*10000*10000
a2=100_0000_0000
print(a0==a1 & a1==a2)
#运行结果：True

#交换变量值
a=1;b=2
a,b=b,a
print('a =',a,'b =',b)、
#运行结果：a = 2 b = 1

#连续比较式
a=99
if 95<=a<=100:
    print('太优秀啦！')

#字符串乘法
print('------------------------------')
print('-'*30)
print('#'*30)
print('@'*30)

#运行结果：------------------------------
		  ------------------------------
		  ##############################
		  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 

#列表拼接与乘法
a=[1,2,3]
b=[4,5,6,7]
print('a+b =',a+b)
print('a*3 =',a*3)
#运行结果：
#a+b = [1, 2, 3, 4, 5, 6, 7]
#a*3 = [1, 2, 3, 1, 2, 3, 1, 2, 3]

#列表切片
a=[1,2,3,4,5,6,7,8,9]
a[3:-2] #运行结果：[4, 5, 6, 7]
a[-1] #运行结果：9
a[:3] #运行结果：[1, 2, 3]
a[-3:] #运行结果：[7, 8, 9]

#解包
a = (1,2,3)
x,y,z=a
print('a =',a,'\nx =',x,'y =',y,'z =',z)
#打包
b = (x,y,z)
print('b =',b)
#运行结果：a = (1, 2, 3) 
		  x = 1 y = 2 z = 3
		  b = (1, 2, 3)

#With语句
with open('test.txt','r') as f:
    data = f.read()

#列表解析式
a=[1,2,3,4]
b=[e+233 for e in a]
print(b)