import语句

import语句
import math
math.sqrt(4)
2.0
#from...import...从模块中导入指定的部分到当前命令空间中
from math import sqrt
sqrt(4)
2.0
#导入多个函数
from math import sqrt,log10
print(sqrt(4))
print(log10(10))
2.0
1.0
#给math起个简短的名称
import math as mm
mm.sqrt(4)
2.0
import numpy as np
import pandas as pa
#导入math模块下的所有函数
from math import *
print(sqrt(4))
print(floor(3.8))
2.0
3
import this #python之禅
The Zen of Python, by Tim Peters

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!