python 开发工具库资料合集

Posted 2022-11-26 帅气的黑桃J

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1.Introduction

record some common command

2.grammar

doc:

lambda

import time

# 1.变量转变为函数
ans = lambda x,y : x+y
print(ans(1,3))

# 2.覆盖其他函数的功能
time.sleep=lambda x:None
# 输出无效
time.sleep(3)

# switch的使用
def switch(options):
    funcdic = 
        1: lambda: method1(),
        2: lambda: method2(),
        3: lambda: method3(),
    
    return funcdic[options]()

3. Anaconda

doc:

在anaconda中配置虚拟环境教程

4.File & os

doc:

4.1 os file operate

import os

# 返回当前目录
os.getcwd()

# 返回上一级目录地址
os.path.abspath(os.path.join(os.getcwd(), '..'))

5. Crawler（request+beautifulsoup）

doc:

5.1 A easy request Demo

import requests

base_url = 'https://www.baidu.com/more/'

response = requests.get(base_url)
response.encoding='utf-8'
print(response.text)

5.2 Beautiful soup demo1

from bs4 import BeautifulSoup
import requests

base_url = 'https://www.shanghairanking.cn/rankings/bcur/2022'

if __name__ == '__main__':
    print('[info] start')
    response = requests.get(base_url)
    response.encoding='utf-8'
    # get soup
    soup = BeautifulSoup(response.text,'lxml')

    # get rank info of one page
    uni_html_info_list = soup.find('table').find('tbody').find_all('tr')

    cols = "0:6^10\\t1:6^10\\t2:6^10\\t3:6^10\\t4:^10\\t5:^10\\t"
    print(cols.format('排名', '大学名称', '省市', '类型', '总分', '办学层次', chr(12288)))

    # analysis every uni info
    for uni_item_html_info in uni_html_info_list:
        uni_item_info = []
        uni_item_info.append(uni_item_html_info.find_all('td')[0].find('div').string.strip())
        uni_item_info.append(uni_item_html_info.find_all('td')[1].find_all('a')[0].string)
        uni_item_info.append(uni_item_html_info.find_all('td')[2].contents[0].strip())
        uni_item_info.append(uni_item_html_info.find_all('td')[3].contents[0].strip())
        uni_item_info.append(uni_item_html_info.find_all('td')[4].contents[0].strip())
        uni_item_info.append(uni_item_html_info.find_all('td')[5].contents[0].strip())
        print(cols.format(uni_item_info[0],uni_item_info[1],uni_item_info[2],uni_item_info[3],uni_item_info[4],uni_item_info[5],chr(12288)))
    print('[info] end')

5.3 Beautiful soup demo2

from bs4 import BeautifulSoup
import requests

base_url = 'https://www.cae.cn'
home_url = '/cae/html/main/col48/column_48_1.html'

if __name__ == '__main__':
    print('[info] start')
    response = requests.get(base_url+home_url)
    response.encoding='utf-8'
    # get soup
    soup = BeautifulSoup(response.text,'lxml')

    # get every ys info url
    for item_list in soup.find_all(name='div', attrs='class': 'ysxx_namelist clearfix'):
        for item in item_list.find_all('a'):
            # ys_name = item.string
            item_url = item.get('href')
            item_response = requests.get(base_url+item_url)
            item_soup = BeautifulSoup(item_response.text,'lxml')
            ys_description = ''
            for item_p in item_soup.find(name='div',attrs='class': 'intro').find_all('p'):
                ys_description = ys_description + item_p.string.strip()

            with open("ys_description.txt", "a+",encoding='utf-8') as f:  # 打开文件
                f.write(ys_description+'\\n')  # 读取文件
                f.close()
            print(ys_description)

6. Django

learning info:

7. pymysql

doc:

8.JSON

doc:

Python中的json操作
dumps(obj covert json)

import json

# dumps可以格式化所有的基本数据类型为字符串
data1 = json.dumps([])         # 列表
print(data1, type(data1))
data2 = json.dumps(2)          # 数字
print(data2, type(data2))
data3 = json.dumps('3')        # 字符串
print(data3, type(data3))
dict = "name": "Tom", "age": 23   # 字典
data4 = json.dumps(dict)
print(data4, type(data4))

# 将dict中的数据写入文件中
with open("test.json", "w", encoding='utf-8') as f:
    # indent 超级好用，格式化保存字典，默认为None，小于0为零个空格
    f.write(json.dumps(dict, indent=4))
    json.dump(dict, f, indent=4)  # 传入文件描述符，和dumps一样的结果

loads（str covert to json）

import json

dict = '"name": "Tom", "age": 23'   # 将字符串还原为dict
data1 = json.loads(dict)
print(data1, type(data1))

with open("test.json", "r", encoding='utf-8') as f:
    data2 = json.loads(f.read())    # load的传入参数为字符串类型
    print(data2, type(data2))
    f.seek(0)                       # 将文件游标移动到文件开头位置
    data3 = json.load(f)
    print(data3, type(data3))

9.pyqt

doc:

QMessageBox.about(self, "提示", "需要选中一项内容")

user = self.lineEdit_user.text()

10.re

doc:

11.numpy

doc:

numpy教程07—ndarray的保存与加载

11.1 numpy file operate

import numpy as np
a = np.random.rand(2, 3)
print(a)

# save as npy
np.save('my_array', a)
# read from npy
a_loaded = np.load('my_array.npy')
print(a_loaded)

# save as 
np.savetxt('my_array.csv', a, delimiter=',')
a_loaded = np.loadtxt('my_array.csv', delimiter=',')
print(a_loaded)