5 interesting Python scripts

Python can be used in many directions, such as crawlers, predictive analysis, GUI, automation, image processing, visualization, etc. It may only take a dozen lines of code to achieve cool functions.

Because Python is a dynamic scripting language, the code logic is much simpler than Java, and a lot less code is needed to achieve the same function. Moreover, the Python ecosystem has many third-party tool libraries that encapsulate functions in packages. You only need to call the interface to use complex functions.

Here are a few simple and fun script examples. Beginners can follow the code and quickly master python syntax.

1. Use PIL, Matplotlib, and Numpy to repair blurry old photos

# encoding=utf-8
import numpy as np
import matplotlib.pyplot as plt
from PIL import Image
import os.path
# 读取图片
img_path = "E:\\test.jpg"
img = Image.open(img_path)

# 图像转化为numpy数组
img = np.asarray(img)
flat = img.flatten()

# 创建函数
def get_histogram(image, bins):
    # array with size of bins, set to zeros
    histogram = np.zeros(bins)
    # loop through pixels and sum up counts of pixels
    for pixel in image:
        histogram[pixel] += 1
    # return our final result
    return histogram

# execute our histogram function
hist = get_histogram(flat, 256)

# execute the fn
cs = np.cumsum(hist)

# numerator & denomenator
nj = (cs - cs.min()) * 255
N = cs.max() - cs.min()

# re-normalize the cumsum
cs = nj / N

# cast it back to uint8 since we can't use floating point values in images
cs = cs.astype('uint8')

# get the value from cumulative sum for every index in flat, and set that as img_new
img_new = cs[flat]

# put array back into original shape since we flattened it
img_new = np.reshape(img_new, img.shape)

# set up side-by-side image display
fig = plt.figure()
fig.set_figheight(15)
fig.set_figwidth(15)

# display the real image
fig.add_subplot(1, 2, 1)
plt.imshow(img, cmap='gray')
plt.title("Image 'Before' Contrast Adjustment")

# display the new image
fig.add_subplot(1, 2, 2)
plt.imshow(img_new, cmap='gray')
plt.title("Image 'After' Contrast Adjustment")
filename = os.path.basename(img_path)

# plt.savefig("E:\\" + filename)
plt.show()

2. Compress files in batches using the zipfile library

import os
import zipfile
from random import randrange


def zip_dir(path, zip_handler):
    for root, dirs, files in os.walk(path):
        for file in files:
            zip_handler.write(os.path.join(root, file))


if __name__ == '__main__':
    to_zip = input("""
Enter the name of the folder you want to zip
(N.B.: The folder name should not contain blank spaces)
>
""")
    to_zip = to_zip.strip() + "/"
    zip_file_name = f'zip{randrange(0,10000)}.zip'
    zip_file = zipfile.ZipFile(zip_file_name, 'w', zipfile.ZIP_DEFLATED)
    zip_dir(to_zip, zip_file)
    zip_file.close()
    print(f'File Saved as {zip_file_name}')

3. Use tkinter to create a calculator GUI

tkinter is Python's own GUI library, suitable for beginners to practice creating small software.

import tkinter as tk

root = tk.Tk()  # Main box window
root.title("Standard Calculator")  # Title shown at the title bar
root.resizable(0, 0)  # disabling the resizeing of the window

# Creating an entry field:
e = tk.Entry(root,
             width=35,
             bg='#f0ffff',
             fg='black',
             borderwidth=5,
             justify='right',
             font='Calibri 15')
e.grid(row=0, column=0, columnspan=3, padx=12, pady=12)


def buttonClick(num):  # function for clicking
    temp = e.get(
    )  # temporary varibale to store the current input in the screen
    e.delete(0, tk.END)  # clearing the screen from index 0 to END
    e.insert(0, temp + num)  # inserting the incoming number input


def buttonClear():  # function for clearing
    e.delete(0, tk.END)

# 代码过长，部分略

4. Convert PDF to Word file

Using the pdf2docx library, you can convert PDF files to Word format

from pdf2docx import Converter
import os 
import sys

# Take PDF's path as input 
pdf = input("Enter the path to your file: ")
assert os.path.exists(pdf), "File not found at, "+str(pdf)
f = open(pdf,'r+')

#Ask for custom name for the word doc
doc_name_choice = input("Do you want to give a custom name to your file ?(Y/N)")

if(doc_name_choice == 'Y' or doc_name_choice == 'y'):
    # User input
    doc_name = input("Enter the custom name : ")+".docx"
    
else:
    # Use the same name as pdf
    # Get the file name from the path provided by the user
    pdf_name = os.path.basename(pdf)
    # Get the name without the extension .pdf
    doc_name =  os.path.splitext(pdf_name)[0] + ".docx"

    
# Convert PDF to Word
cv = Converter(pdf)

#Path to the directory
path = os.path.dirname(pdf)

cv.convert(os.path.join(path, "", doc_name) , start=0, end=None)
print("Word doc created!")
cv.close()

5. Python automatically sends emails

Using smtplib and email library, scripts can be used to send emails.

import smtplib
import email
# 负责构造文本
from email.mime.text import MIMEText
# 负责构造图片
from email.mime.image import MIMEImage
# 负责将多个对象集合起来
from email.mime.multipart import MIMEMultipart
from email.header import Header

# SMTP服务器,这里使用163邮箱
mail_host = "smtp.163.com"
# 发件人邮箱
mail_sender = "******@163.com"
# 邮箱授权码,注意这里不是邮箱密码,如何获取邮箱授权码,请看本文最后教程
mail_license = "********"
# 收件人邮箱，可以为多个收件人
mail_receivers = ["******@qq.com","******@outlook.com"]

mm = MIMEMultipart('related')

# 邮件主题
subject_content = """Python邮件测试"""
# 设置发送者,注意严格遵守格式,里面邮箱为发件人邮箱
mm["From"] = "sender_name<******@163.com>"
# 设置接受者,注意严格遵守格式,里面邮箱为接受者邮箱
mm["To"] = "receiver_1_name<******@qq.com>,receiver_2_name<******@outlook.com>"
# 设置邮件主题
mm["Subject"] = Header(subject_content,'utf-8')

# 邮件正文内容
body_content = """你好，这是一个测试邮件！"""
# 构造文本,参数1：正文内容，参数2：文本格式，参数3：编码方式
message_text = MIMEText(body_content,"plain","utf-8")
# 向MIMEMultipart对象中添加文本对象
mm.attach(message_text)

# 二进制读取图片
image_data = open('a.jpg','rb')
# 设置读取获取的二进制数据
message_image = MIMEImage(image_data.read())
# 关闭刚才打开的文件
image_data.close()
# 添加图片文件到邮件信息当中去
mm.attach(message_image)

# 构造附件
atta = MIMEText(open('sample.xlsx', 'rb').read(), 'base64', 'utf-8')
# 设置附件信息
atta["Content-Disposition"] = 'attachment; filename="sample.xlsx"'
# 添加附件到邮件信息当中去
mm.attach(atta)

# 创建SMTP对象
stp = smtplib.SMTP()
# 设置发件人邮箱的域名和端口，端口地址为25
stp.connect(mail_host, 25)  
# set_debuglevel(1)可以打印出和SMTP服务器交互的所有信息
stp.set_debuglevel(1)
# 登录邮箱，传递参数1：邮箱地址，参数2：邮箱授权码
stp.login(mail_sender,mail_license)
# 发送邮件，传递参数1：发件人邮箱地址，参数2：收件人邮箱地址，参数3：把邮件内容格式改为str
stp.sendmail(mail_sender, mail_receivers, mm.as_string())
print("邮件发送成功")
# 关闭SMTP对象
stp.quit()

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