9.29

(1)时间

import datetime

from datetime import datetime,timedelta   #模块包含一个datetime类

dt=datetime(2011,3,2,13,25)
print(dt)
now=datetime.now()   #获取当前日期
mydt=datetime(2019,1,1)  #获取指定日期
print(now,mydt)
print(type(now))
print(now-mydt)   #当前日期距离指定日期多久
print(dt.year)
print(dt.month)
print(dt.day)
print(dt.hour)
print(dt.minute)
print(dt.second)
print(dt.microsecond)

print(now + timedelta(hours=10))   #当前日期加十小时
print(now - timedelta(days=1))   #当前日期减一天
print(now + timedelta(days=2, hours=12))   #当前日期加两天十二小时
print(now - timedelta(days=100))   #100天前是几号?
print(mydt-now) #今年还有多少天？

 

（2）列表

def h(n):#定义一个函数
    a =list(range(n))
    b = list(range(1,5*n,5))
    c=[]
    for i in range(len(a)):
        c.append(a[i]**2+b[i]**3)
    return(c)
print(h(10))

a =list(range(10))
b = list(range(1,50,5))
c=[]
for i in range(len(a)):
    c.append(a[i]**2+b[i]**3)
print(a,b,c)

 

 

（3）自定义函数

def h(n):#定义一个函数
    a =list(range(n))
    b = list(range(1,5*n,5))
    c=[]
    for i in range(len(a)):
        c.append(a[i]**2+b[i]**3)
    return(c)
print(h(10))

import numpy

def g(n):
    a = numpy.arange(n)
    b = numpy.arange(0,5*n,5)
    c = a**2+b**3
    return(c)
print(g(10))


from datetime import datetime
start = datetime.now()
h(100000)
delta = datetime.now()-start
print(delta)


start=datetime.now()
g(10000)
delta=datetime.now()-start
print(delta)