包

Python 入门

Hugo Bowne-Anderson

Data Scientist at DataCamp

学习动力

函数和方法功能强大
Python 发行版中是否包含所有代码？
- 代码库过于庞大：混乱不堪
- 有许多不会用到的代码
- 维护困难

包

Python 脚本目录
每个脚本即代表一个模块
指定函数、方法、类型
有数千个可用包
- NumPy
- Matplotlib
- scikit-learn

Screen Shot 2019-09-08 at 9.18.56 AM.png

安装包

https://pip.pypa.io/en/stable/installation/
下载 get-pip.py
终端：
- python3 get-pip.py
- pip3 install numpy

导入包

import numpy

array([1, 2, 3])

NameError: name 'array' is not defined

numpy.array([1, 2, 3])

array([1, 2, 3])

import numpy as np

np.array([1, 2, 3])

array([1, 2, 3])

from numpy import array

array([1, 2, 3])

array([1, 2, 3])

from numpy import array

my_script.py

from numpy import array


fam = ["liz", 1.73, "emma", 1.68, 
    "mom", 1.71, "dad", 1.89]

...

fam_ext = fam + ["me", 1.79]

...

print(str(len(fam_ext)) + " elements in fam_ext")

...

np_fam = array(fam_ext)

使用了 NumPy，但不是很清楚

import numpy

import numpy as np

fam = ["liz", 1.73, "emma", 1.68, 
    "mom", 1.71, "dad", 1.89]

...

fam_ext = fam + ["me", 1.79]

...

print(str(len(fam_ext)) + " elements in fam_ext")

...

np_fam = np.array(fam_ext) # Clearly using NumPy

动手练一练！

Python 入门