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Python Because of the simplicity and readability of its code, it has become a very popular language . It's one of the simplest languages you choose . If you are python Beginners of basic concepts , So this is the best time to learn to write better code .

python There are many techniques that can improve the program better than before . This article will help you understand python Various techniques available in . Keep practicing them , Until it becomes part of your programming habits .

I will share 30 It's a magic Python skill To help you write better code , It will be divided into two times to share ~

today Share first 15 individual , Let's see ！

01- Multiple assignment of variables

Python Allows us to assign values to multiple variables in a row . You can use commas to separate variables . Multitasking on the front line has many advantages . It can be used to assign multiple values to multiple variables or to assign multiple values to a single variable name . Let's make a problem statement , Where we must set the value 50 and 60 Assign to a variable a and b. The general code is as follows .

a = 50
b = 60
print(a,b)
print(type(a))
print(type(b)) 

Output

50
60
<class 'int'>
<class 'int'> 

Conditions I- Value equals variable

When a variable is equal to multiple assignments , Each value will be stored in all variables .

a , b = 50 , 60
print(a,b)
print(type(a))
print(type(b)) 

Output

50
60
<class 'int'>
<class 'int'> 

The two programs give the same results . This is the benefit of using a row value assignment .

Conditions II- Value greater than variable

Let's try increasing the number of values in a program . You can assign multiple values to a single variable . When assigning multiple values to a variable , We must use an asterisk before the variable name .

a , *b = 50 , 60 , 70
print(a)
print(b)
print(type(a))
print(type(b)) 

Output

50
[60, 70]
<class 'int'>
<class 'list'> 

The first value is assigned to the first variable . The second variable will collect values from the given values . This will create a list type object .

Conditions III- Multivariable a value

We can assign a value to multiple variables . Each variable will be separated by an equal sign .

a = b = c = 50
print(a,b,c)
print(type(a))
print(type(b))
print(type(c)) 

Output

50 50 50
<class 'int'>
<class 'int'>
<class 'int'> 

02- Exchange two variables

Exchange is the process of exchanging the values of two variables with each other . This is useful in many operations of Computer Science . ad locum , I have written two main methods for programmers to exchange knowledge and the best solution .

Method I- Use temporary variables

This method uses temporary variables to store some data . The following code is written using temporary variable names .

a , b = 50 , 60
print(a,b)
temp = a+b
#a=50 b=60 temp=110
b = a
#a=50 b=50 temp=110
a = temp-b
#a=60 b=50 temp=110
print("After swapping:",a,b) 

Output

50 60
After swapping: 60 50 

Method II- Do not use temporary variables

The following code exchanges variables without using temporary variables .

a , b = 50 , 60
print(a,b)
a = a+b
#a=110 b=60
b = a-b
#a=110 b=50
a = a-b
#a=60 b=50
print("After swapping:",a,b) 

Output

50 60
After swapping: 60 50 

Method III-Python Excellent solutions in

This is the use of python Another way to exchange variables . In the last section , We learned about multiple assignments . We can use the concept of exchange .

a , b = 50 , 60
print(a,b)
a , b = b , a
print("After swapping",a,b) 

Output

50 60
After swapping 60 50 

03- Reverse string

There is another cool technique that can be used in python Reverse string in . The concept used to invert a string is called string slicing . You can use the symbol... After the variable name [::-1] Invert any string .

my_string = "MY STRING"
rev_string = my_string[::-1]
print(rev_string) 

Output

GNIRTS YM 

04- Split words in one line

No special algorithm is needed to split words into one line . So , We can use keywords split(). ad locum , I wrote two ways to segment words .

Method 1 - Using the iterative method

my_string = "This is a string in Python"
start = 0
end = 0
my_list = []
for x in my_string:
end=end+1
if(x==' '):
my_list.append(my_string[start:end])
start=end+1
my_list.append(my_string[start:end+1])
print(my_list) 

Output

['This ', 'is ', 'a ', 'string ', 'in ', 'Python']

Method II- Use the split function

my_string = "This is a string in Python"
my_list = my_string.split(' ')
print(my_list) 

Output

['This ', 'is ', 'a ', 'string ', 'in ', 'Python'] 

05- Line up the word list

This is the opposite of the previous process . In this part , We will use join Function to convert a list of words to a single line . The use of join Syntax of functions .

grammar ："" .join(string)

my_list = ['This' , 'is' , 'a' , 'string' , 'in' , 'Python']
my_string = " ".join(my_list) 

Output

This is a string in Python 

06- Print string multiple times

We can use the multiplication operator to print strings many times . This is a very effective way to repeat strings .

n = int(input("How many times you need to repeat:"))
my_string = "Python\n"
print(my_string*n) 

Output

How many times you need to repeat:3
PythonPythonPython 

07- Join two strings using the addition operator

Can be used without join Function to connect various strings . We can only use the addition operator (+) To perform this operation .

a = "I Love "
b = "Python"
print(a+b) 

Output

I Love Python 

08- Multiple conditional operators

Two can combine two or more conditional operators in a program , We can use logical operators . however , You can get the same result through the link operator . for example , If we need the value of the variable to be greater than 10 And less than 20 When printing something , The code will be similar to the following .

a = 15
if (a>10 and a<20):
print("Hi") 

In its place , We can combine conditional operators into a single expression .

a = 15
if (10 < a < 20):
print("Hi") 

Output

Hi 

09- Find the most frequent elements in the list

Elements that appear most of the time in the list , Then it will become the most frequent element in the list . The following code snippet will help you get the most frequent elements from the list .

my_list = [1,2,3,1,1,4,2,1]
most_frequent = max(set(my_list),key=my_list.count)
print(most_frequent) 

Output

1 

10- Find the occurrence of all elements in the list

The previous code will provide the most frequent values . If we need to know the appearance of all the unique elements in the list , You can use the collection module . The assembly is python A great module in , It provides powerful functions . Counter Method provides a dictionary with elements and occurrence pairs .

from collections import Counter
my_list = [1,2,3,1,4,1,5,5]
print(Counter(my_list)) 

Output

Counter({1: 3, 5: 2, 2: 1, 3: 1, 4: 1}) 

11- Check the puzzle of two strings

If a string consists of characters in another string , Then the two strings are word puzzles . We can do it in collections The same... Is used in the module Counter Method .

from collections import Counter
my_string_1 = "RACECAR"
my_string_2 = "CARRACE"
if(Counter(my_string_1) == Counter(my_string_2)):
print("Anagram")
else: print("Not Anagram") 

Output

Anagram 

12- Create a sequence of numbers with ranges

function range() Useful for creating a sequence of numbers . In many code snippets , It can be very useful . The syntax of the scope function is written here .

grammar ：range( Start , end , step )

Let's try to create an even list .

my_list = list(range(2,20,2))
print(my_list) 

Output

[2, 4, 6, 8, 10, 12, 14, 16, 18] 

13- Repeat the elements many times

Similar to string multiplication , We can use the multiplication operator to create a list of filled elements multiple times .

my_list = [3]
my_list = my_list*5
print(my_list) 

Output

[3, 3, 3, 3, 3] 

14- Use conditions in ternary operators

in the majority of cases , We are Python Nested conditional structures are used in . In addition to using nested structures , You can also replace a line with the help of ternary operators . The syntax is given below .

grammar ：if True then Statement1 else Statement2

if age > 20 then age = 25, print（"czz"）else print（" unqualified "）

Output

 qualified 

15- Use Python List derived expressions

A list derivation expression is a very compact way to create a list from another list . Look at the code below . The first is written using simple iterations , The second is understood using lists .

square_list = []
for x in range(1,10):
temp = x**2 square_list.append(temp)
print(square_list) 

Output

[1, 4, 9, 16, 25, 36, 49, 64, 81] 

Use a list to derive an expression

square_list = [x**2 for x in range(1,10)]
print(square_list) 

Output

[1, 4, 9, 16, 25, 36, 49, 64, 81] 

Last

Okay , Today my sharing is over , The other half , I'll share it with you next time