python之命令行可以做的事儿

• 前言

说起python，大家都知道可以做很多有趣的事儿。知乎、CSDN上很多大牛做过很多或高大上或实用的事儿。参见这篇文章Python趣味代码整合之提升学生编程兴趣，

另外，我发现命令行也可以做很多事。以下是我的一些想法，欢迎大家补充！

• 环境配置与模块安装

1. 运行环境：Python3.6+cmd命令行
2. 依赖模块：requests,bs4,numpy,PIL,webbrowser,subprocess

模块具体安装方法参见网上教程

• 实现功能

• 查询天气

早上起来，想看今天的天气，打开电脑，百度搜索地点，简直太麻烦。不妨命令行输入指令快速获取。（请忽略手机查看等其他更快捷方式，虽然相比较而言前者有些不足，但，存在即有意义，命令行也可以做很多事。）

import requests
from bs4 import BeautifulSoup
#获取www.tianqi.com的天气,参数：地名拼音
def data_of_tianqi(addr):
    response = requests.get("https://www.tianqi.com/"+addr+"/")
    soup = BeautifulSoup(response.text, 'html.parser')
    tag_dd = soup.find_all(name='dd')
    tag_span = soup.find_all(name='span')[0]
    temp = str(soup.find_all(name='b')[0])[3:-4]#温度
    city_html = BeautifulSoup(str(tag_dd[0]), 'html.parser')
    city = str(city_html.find_all(name='h2'))[5:-6]#城市
    if str(tag_dd[1])[41:43]=='</':
        time=str(tag_dd[1])[17:41]
    else:
        time=str(tag_dd[1])[17:43]
    weather_and_temp = str(tag_span)[9:-7].split('</b>')
    weather = weather_and_temp[0]#天气
    temp = str(soup.find_all(name='b')[0])[3:-4]#实时温度
    temp_from_to = weather_and_temp[1]#温度范围
    shidu = str(tag_dd[3]).replace("</b>","").replace("</dd>","").split("<b>")[1]#湿度
    fengxaing = str(tag_dd[3]).replace("</b>","").replace("</dd>","").split("<b>")[2]#风向
    ziwaixian = str(tag_dd[3]).replace("</b>","").replace("</dd>","").split("<b>")[3]#紫外线
    other_info = str(tag_dd[4])[57:-12].replace('</h5><h6>','<br/>').replace('</h6><span>','<br/>').split('<br/>')#空气质量、PM、日出、日落
    print('城市：'+city)
    print('时间：'+time)
    print('天气：'+weather)
    print('实时温度：'+temp+'  '+'温度范围：'+temp_from_to)
    print(shidu+'  '+fengxaing+'  '+ziwaixian)
    print(other_info[0]+'  '+other_info[1])
    print(other_info[2]+'  '+other_info[3])

代码参考了一些网上资料（表示感谢），再做了相应修改，展示更美观一些。

在命令行输入python start.py weather chengdu，便得到的成都天气信息：

• .浏览器操作

想在命令行百度搜索、360搜索、必应搜索？想快速打开指定网页？没关系，这些都可以实现！

# -*- coding: utf-8 -*-
"""
Created on Tue Aug  7 11:06:53 2018
快速搜索（百度、360、必应）&快速打开常用网站
csdn 百度 MOOC  新华社
@author: Administrator
"""
import webbrowser
def search(word):
    if word[0]=='baidu':
        print('百度搜索'+word[1]+'内容正在打开。。。')
        webbrowser.open('https://www.baidu.com/s?wd='+word[1])
    if word[0]=='360':
        print('360搜索'+word[1]+'内容正在打开。。。')
        webbrowser.open('https://www.so.com/s?q='+word[1])
    if word[0]=='biying':
        print('必应搜索'+word[1]+'内容正在打开。。。')
        webbrowser.open('http://global.bing.com/search?q='+word[1])
def webopen(word):
    name=['csdn','百度','MOOC','新华社']
    words=['csdn','baidu','mooc'，'xhs']
    if type(word)==list:
        search(word)
    elif word not in words:
        print('访问失败！')
    else:
        for i in range(len(words)):
            if word==words[i]:
                print('您访问的'+name[i]+'正在打开。。。')
                break
        if i==0:
            webbrowser.open('https://download.csdn.net/my')
        elif i==1:
            webbrowser.open('https://www.baidu.com/')
        elif i==2:
            webbrowser.open('http://www.icourse163.org/home.htm?userId=7816710#/home/course')
        elif i==3:
            webbrowser.open('http://www.xinhuanet.com/english/home.htm')

由于一些隐私原因，我删除了部分我常去的一些网站，你当然也可以按照格式添加属于你的网站访问快捷方式。

• 启动应用程序

同样，用subprocess模块可以打开计算机上的应用程序。虽然现在电脑软件大多有快捷方式，但是用命令行打开其实也挺不错的。

# -*- coding: utf-8 -*-
"""
Created on Wed Aug  8 10:59:15 2018
命令行启动应用程序
@author: Administrator
"""
import subprocess
def setup(word):
    words=['excel','word','ppt','visio','pycharm']
    if word not in words:
        print('打开失败！')
    else:
        for i in range(len(words)):
            if word==words[i]:
                print(word+'应用程序正在打开中。。。')
                break
        if i==0:
            subprocess.Popen('C:\\Program Files\\Microsoft Office\\Office16\\EXCEL.exe')
        if i==1:
            subprocess.Popen('C:\\Program Files\\Microsoft Office\\Office16\\WINWORD.exe')
        if i==2:
            subprocess.Popen('C:\\Program Files\\Microsoft Office\\Office16\\POWERPNT.exe')
        if i==3:
            subprocess.Popen('C:\\Program Files\\Microsoft Office\\Office16\\VISIO.exe')
        if i==4:
            subprocess.Popen('C:\\Program Files\\JetBrains\\PyCharm Community Edition 2017.2.4\\bin\\pycharm64')

• 图片转字符

参考《python 极客项目编程》这本书有关于ASCII文本图形的代码，并做相应修改。如下：

"""
ascii.py

A python program that convert images to ASCII art.

Author: Mahesh Venkitachalam
"""

import numpy as np
from PIL import Image
# gray scale level values from:
# http://paulbourke.net/dataformats/asciiart/

# 70 levels of gray
gscale1 = "$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,\"^`'. "
# 10 levels of gray
gscale2 = '@%#*+=-:. '

def getAverageL(image):
    """
    Given PIL Image, return average value of grayscale value
    """
    # get image as numpy array
    im = np.array(image)
    # get shape
    w,h = im.shape
    # get average
    return np.average(im.reshape(w*h))

def covertImageToAscii(fileName, cols, scale, moreLevels):
    """
    Given Image and dims (rows, cols) returns an m*n list of Images
    """
    # declare globals
    global gscale1, gscale2
    # open image and convert to grayscale
    image = Image.open(fileName).convert('L')
    # store dimensions
    W, H = image.size[0], image.size[1]
    print("input image dims: %d x %d" % (W, H))
    # compute width of tile
    cols=int(cols)
    w = W/cols
    # compute tile height based on aspect ratio and scale
    h = w/scale
    # compute number of rows
    rows = int(H/h)

    print("cols: %d, rows: %d" % (cols, rows))
    print("tile dims: %d x %d" % (w, h))

    # check if image size is too small
    if cols > W or rows > H:
        print("Image too small for specified cols!")
        exit(0)

    # ascii image is a list of character strings
    aimg = []
    # generate list of dimensions
    for j in range(rows):
        y1 = int(j*h)
        y2 = int((j+1)*h)
        # correct last tile
        if j == rows-1:
            y2 = H
        # append an empty string
        aimg.append("")
        for i in range(cols):
            # crop image to tile
            x1 = int(i*w)
            x2 = int((i+1)*w)
            # correct last tile
            if i == cols-1:
                x2 = W
            # crop image to extract tile
            img = image.crop((x1, y1, x2, y2))
            # get average luminance
            avg = int(getAverageL(img))
            # look up ascii char
            if moreLevels:
                gsval = gscale1[int((avg*69)/255)]
            else:
                gsval = gscale2[int((avg*9)/255)]
            # append ascii char to string
            aimg[j] += gsval

    # return txt image
    return aimg

# main() function
def ascii_write(word):
    word=['D:\\pycodes\\命令行快速访问\\asc_data\\'+word[0],word[1]]
    imgFile = word[0]
    # set output file
    outFile = 'D:\\pycodes\\命令行快速访问\\asc_data\\out.txt'
    # set scale default as 0.43 which suits a Courier font
    scale = 0.43
    # set cols
    cols = word[1]
    print('generating ASCII art...')
    # convert image to ascii txt
    aimg = covertImageToAscii(imgFile, cols, scale,0)
    # open file
    f = open(outFile, 'w')
    # write to file
    for row in aimg:
        f.write(row + '\n')
    # cleanup
    f.close()
    print("ASCII art written to %s" % outFile)

命令行上输入python start.py pyascii panda1.jpg 200，回车，便得到由字符拼接的萌萌的大熊猫宝宝啦。由于截图大小有限，这里仅放上它炯炯有神的大眼睛。

萌死我啦！注意：图片名后的数字代表像素，数字越大，图片细节越清晰，但txt文档打开一个界面看不完（必须滑动）

• 主程序

你可能会奇怪，为什么命令行执行的都是start.py文件，难道不可以直接运行各个子程序吗？本来是可以的，但是为了追求简洁统一，避免C:\Users\Administrator\目录下放到py文件过多，便写了个主程序start.py（必须放于C:\Users\Administrator\目录下！）。

Created on Mon Aug  6 21:05:09 2018

@author: Administrator
命令行快速查询、启动、运行
"""
import sys
sys.path.append('D:\\pycodes\\命令行快速访问')
import weather
import pyascii
import webopen
import setup
if len(sys.argv) < 2:
    sys.exit()
code= ' '.join(sys.argv[1:2])
word= ' '.join(sys.argv[2:3])
if len(sys.argv)>3:
    t=' '.join(sys.argv[3:4])
    word=[word,t]
codes=['weather','pyascii','webopen','setup']
if code not in codes:
    print('Wrong instructions!')
else:
    for i in range(len(codes)):
        if code==codes[i]:
            print('Instructions will be executed！')
            break
    if i==0:
        weather.data_of_tianqi(word)
    elif i==1:
        pyascii.ascii_write(word)
    elif i==2:
        webopen.webopen(word)
    elif i==3:
        setup.setup(word)

Github传送门：https://github.com/SCHaoZhang/python/tree/master/python_cmd

如果你还有其他的好点子，请分享给我哈！如果文中有不足之处，请私聊哈！