To get you started in Python in 10 minutes, I spent 5 hours writing 7 cases and this article!!

preface

Recently, I went through the basics of Python systematically and learned how to learn it quickly. The normal logic is to practice cases while reading basic knowledge, which is a process of thinning books from thick to thin.

However, nowadays the pace is so fast, especially the Internet companies, excluding the time of staying at home to see the children on weekends, there is almost no time and energy for deep learning, so this article was born.

In this paper, the basic knowledge of Python can be quickly mastered by combining python knowledge directly with cases.

Name of the case

Calculated circle area
Input characters and output in reverse order
Number game
Output poetry in verse format
Top 10 Words in statistics text (TXT)
Web page element extraction
Text progress bar

Calculated circle area

Print uses the format () function to format the output.

Fixed formula:

print< output string template >.format(< variable1>, < variable2>, < variable3>))Copy the code

Implementation code:

 r = 25    # The radius of the circle is 25
 area = 3.1415 * r * r  # The formula for circles
 print(area) 
 print('{:.2f}'.format(area) )  Print only two decimal places
Copy the code

Novice easy mistakes:

The string template format ‘{:.2f}’ before format is often miswritten, and one {} corresponds to one of the parameters in format.

Input characters and output in reverse order

The idea: Find the last element and print it.

Knowledge:

Input uses the input function
Calculate the length using the len () function
The output function ends with end= “, adding an empty string after the output character

   # Input text
   s=input('Please enter a text:')  
   # calculate the length of input and assign to I I =len(s)-1
   # reverse loop output
   while i>=0:      
       print(s[i],end=' ')      
       i=i-1
Copy the code

Effect: The code can be executed

Number game

Generate a random number and judge the input number and the random number until the guess is successful.

Knowledge:

Use random.randint() to generate a random number
A while () loop that breaks out of the loop when the condition break is met and continues until the condition is met
The input numeric eval function converts the string type to an integer in conjunction with the input
If tripartite conditional judgment, if elif else format

Implementation code:

import random   
# Generate random number
a=random.randint(0.1000)  
# Count times
count=0    
while True:          
    number=eval(input(Please enter a number between 0 and 1000:))        
    count=count+1  
# compare two numbers
if number>a:      
    print('Lost big')  
elif number<a:      
    print('Lose small')  
else:      
    print('Got it.')     
    break    
print('Number of guesses:',count)
Copy the code

Renderings: The code can be executed

Output poetry in verse format

Original format:

Life must be happy, don’t make the golden bottle empty to the moon.

Born my material will be useful, daughter dispersed also come back.

Output effect:

Don’t make the golden bottle empty to the moon

I was born with a thousand pieces of material will be dispersed to return

Design idea:

Replace all punctuation marks with \n
Text is displayed centered and aligned

Knowledge:

Replace function line.replace(variable name, value to replace)
Center align line.center(width)
Function call, passing the text variable TXT into the replacement function linesplit

txt = Life must be happy, do not make the golden bottle empty to the moon. Born my material will be useful, daughter dispersed also come back. ' ' '
# define a function that replaces punctuation with \n

def linesplit(line) :
    plist = [', '.'! '.'? '.', '.'. '.'! '.'? ']    
    for p in plist:        
        line=line.replace(p,'\n')
    
    return line.split('\n')
linewidth = 30  Predetermined output width

Define a function that implements center alignment
def lineprint(line) : 
    global linewidth    
    print(line.center(linewidth))   
# call function

newlines=linesplit(txt)
for newline in newlines:    
    lineprint(newline)
Copy the code

Count the 10 most frequently used words in a text

Let’s look at the implementation:

Step split:

First, unify the text content to lowercase, using the lower() function
Again, the replace() function replaces special characters in the text with Spaces
Press Spaces to cut the text, using the split () function
Count the number of occurrences of words
Sort the sort() function from highest to lowest frequency
Output in a fixed format, using the format() function

Follow the steps above to implement the code.

First, unify the text content to lowercase, using the lower() function:

 def gettxt() :  
     # read file
     txt=open('hamlet.txt'.'r').read()  
     txt=txt.lower()
Copy the code

Again, the replace() function replaces the special characters in the text with Spaces:

   for ch in ' '!"# $% & () *, +, -, / :; The < = >? @ ^ _ '[\] {|} ~' : 'TXT = TXT. Replace ('') return TXTCopy the code

Press space to split the text, using the split () function:

hmlttxt=gettxt()
words=hmlttxt.split()
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Count the number of occurrences of words:

 counts=0
 for word in words:  
     counts[word]=counts.get(word,0) +1   
     When word is not in words, the return value is 0; when word is in words, the return value is +1, so as to carry out the cumulative count
Copy the code

Sort items by frequency sort() sort()

 items=list(counts.items())
 items.sort(key=lambada x:x[1],reverse=True)
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The x above can be any letter, reverse=True in reverse order, default ascending order.

To output in fixed format, use the format() function:

for i in range(10)  
    word,count=item[i]  
    print('{0: < 10} {1: > 5}'.format(word,count))
Copy the code

Complete code:

First, unify the text content to lowercase, using the lower() function
def gettxt() :    
    txt=open('hamlet.txt'.'r').read()    
    txt=txt.lower()
Replace () replaces special characters in text with Spaces
    for ch in '!" # $% & * () +, -, / :; The < = >? @ [\] ^ _ '{|} ~':        
        txt=txt.replace(ch,' ')    
    return txt
Split the text by space, using the split () function
hamlettxt=gettxt()
words=hamlettxt.split()
# Count words

counts={}
for word in words:    
    counts[word]=counts.get(word,0) +1    
    
Sort the sort() function from highest to lowest frequency
items=list(counts.items())
items.sort(key=lambda x:x[1],reverse=True)
Output in fixed format, using the format() function

for i in range(10):    
    word, count=items[i]    
    print("{0: < 10}, {1: > 5}".format(word,count))
Copy the code

The Web page element extracts the image URL path information

The main purpose of this feature is to replace functions and top-down design ideas.

Effect achieved:The whole function is divided into the following process:

First, extract all the elements of the page
Second, extract the URL path of the image
Then, the path information is output and displayed
Finally, save these paths to a file

We wrap each of the above steps into a function, and finally call main (), which extracts the url path of the image as the core.

Extract all elements of the page

It involves knowledge points: file opening, reading and closing.

 def gethtmllines(htmlpath) :  
  # File open
  f=open(r,'htmlpath',encoding='utf-8')  
  Ls =f.readlines()
  # file close
  f.close()  
  return ls 
Copy the code

Extract the url path of the image

Source:

Knowledge:

The captured address is stored in a list
List split, split() function

 def geturl(ls) :  
  urls=[]  
 for line in ls:    
   if 'img' in line:      
     url=line.split('src=')[-1].split('"') [1]      
     urls.append(url)
Copy the code

The path information is displayed

The for loop outputs path information.

 forLoop outputs path informationdef show(urls) :  
     count=0  
     for url in urls:    
       print('{:2} url{}'.format(count,url))    
       count+=1    
Copy the code

Save these paths to a file

Writing files.

def save(filepath,urls) :  
  f=open(filepate,'w')  
  for url in urls:    
    f.write(url+'\n')  
f.close()
Copy the code

The main() function combines the above functions

def main() :    
    inputfile  = 'nationalgeographic.html'    
    outputfile = 'nationalgeographic-urls.txt'    
    htmlLines = getHTMLlines(inputfile)    
    imageUrls = extractImageUrls(htmlLines)    
    showResults(imageUrls)    
    saveResults(outputfile, imageUrls)
Copy the code

Final code: Python

# Example_8_1.py
#1. Read everything on the page line by line
def getHTMLlines(htmlpath) :    
    f = open(htmlpath, "r", encoding='utf-8')    
    ls = f.readlines()    
    f.close()    
    return ls

#2. Extract the HTTP path
def extractImageUrls(htmllist) :
    urls = []    
    for line in htmllist:        
        if 'img' in line:            
            url = line.split('src=')[-1].split('"') [1]            
            print            
            if 'http' in url:                
                urls.append(url)    
return urls

#3. Output the link address
def showResults(urls) :    
    count = 0    
    for url in urls:        
        print('{:2} URL:{}'.format(count, url))        
        count += 1

#4. Save the result to a file
def saveResults(filepath, urls) :    
    f = open(filepath, "w")    
    for url in urls:        
        f.write(url+"\n")    
f.close()    

def main() :    
    inputfile  = 'nationalgeographic.html'    
    outputfile = 'nationalgeographic-urls.txt'    
    htmlLines = getHTMLlines(inputfile)    
    imageUrls = extractImageUrls(htmlLines)    
    showResults(imageUrls)        
    saveResults(outputfile, imageUrls)
main()
Copy the code

Summary: this small case can master the file read, write operations, you can experience the idea of the function and split() function split.

Text progress bar

Knowledge:

Introducing time library
Print () output format
For I in range(): loop. At the end of the loop, the format function is used to assign its value to the slot.

Implementation code:

import time

def bar(scale) :
    print('=========== Execution start ============')
    for i in range(scale + 1):
        a = The '*' * i
        b = '. ' * (scale - i)
        c = (i / scale) * 100
        print({: '\ r ^ 3.0 f} % [{} - > {}]'.format(c, a, b), end = ' ')
        time.sleep(0.1)
    print('\n=========== End ============')

Copy the code

Effect: Output from 0% to 100%

conclusion

The basic functions of Python are described in the following sections:

The input function implements input
Print prints the result in combination with the format () function
Evaluates the string length len() function
Use random.randint() to generate a random number
The eval function converts the string type to an integer in conjunction with input
If tripartite conditional judgment, if elif else format
Replace function line.replace(variable name, value to replace)
The text content is all lowercase, using the lower() function
Replace () replaces special characters in text with Spaces
The text is sliced, using the split () function
Sort the sort() function from large to small

Why do software testers choose to learn Python rather than Java

Python syntax is concise and clear, and it has a rich and powerful class library that makes it easy to do a lot of things. For starters, Python is the best language to get started with.

Developing small tools in Python is fast and lightweight. In practice, it is very suitable for teams to develop testing tools quickly when testing resources are not sufficient. And usually implements a function, Python has 1/3 to 1/5 of the code of other languages such as Java. At present, more and more big factory’s new tool development, the technology stack all chooses Python. Therefore, mastering Python automated testing techniques to enter the field of software testing and quality assurance is already the best path for newcomers to the testing industry.

If you want to complete the overall deployment of automated tests in your company, Python can help you do this easily:

UI Automation Testing (Python+Selenium, etc.)
Interface tests (Python Requests, etc.)
Performance testing (Python Locust, etc.)
Security testing (Python Scapy, etc.)
Compatibility testing (Python+Selenium, etc.)

Imagine being able to stand up and make money while eating hot pot and singing while others are busy and miserable…

How would you feel in your heart?

How will your boss feel about you?

Collection time

Python Automation test videos, Python automation details, full set of interview questions and other knowledge content. Please click here to help yourself to the group, I hope to help you.

✔️ I made a public programmer yifan, do not regularly share learning dry goods
✔️ if this article is useful to you, remember to like 👍🏻 plus a concern, every one of your likes I seriously as a like ~
✔️ we’ll see you next time! 👋 👋 👋

🌻 Recommended reading:

2021 test development of interview questions and answers (including test base | | automation testing interfaces…). , p. 289
After the byteDance test job interview failed, I reviewed and summarized the reasons for my failure and decided to try again
Ali first internal test development learning manual (complete version), open download! It smells so good
Good foundation? Here are 43 easy to forget Linux operations at work.

To get you started in Python in 10 minutes, I spent 5 hours writing 7 cases and this article!!

preface

Name of the case

Calculated circle area

Input characters and output in reverse order

Number game

Output poetry in verse format

Count the 10 most frequently used words in a text

The Web page element extracts the image URL path information

Text progress bar

conclusion

Why do software testers choose to learn Python rather than Java

Collection time

🌻 Recommended reading:

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