Trending March 2024 # Python For…Else: The ‘Else’ Statement In Loops # Suggested April 2024 # Top 10 Popular

You are reading the article Python For…Else: The ‘Else’ Statement In Loops updated in March 2024 on the website Moimoishop.com. We hope that the information we have shared is helpful to you. If you find the content interesting and meaningful, please share it with your friends and continue to follow and support us for the latest updates. Suggested April 2024 Python For…Else: The ‘Else’ Statement In Loops

In Python, you can place an else statement at the end of a loop.

The else block only runs if a break statement was not used in the loop.

For example, let’s loop through a list of numbers and break the loop if a target number is encountered:

numbers = [1, 5, 43, 2, 7, 9, 19, 10] target = 100 for number in numbers: if number == target: print("Target found, escaping the loop") break else: print("Target not found. The loop ran through all the numbers.")

Output:

Target not found. The loop ran through all the numbers.

The target number was not found. Thus, the break statement was not used. This caused the else statement to run.

This guide teaches how to use the else statement in a for loop/while loop. The theory is backed up with useful real-life examples.

The ‘else’ Statement in Python

Most of the time you use the else statement in an if-else statement to perform actions if the if block is not executed on a False condition.

For example:

age = 10 print("You can drive") else: print("You cannot drive")

Output:

You cannot drive

But you can also place an else statement to the end of a for loop or a while loop. However, the meaning of an else statement in a loop is quite different from what you expected.

The ‘else’ Statement in Loops

When used in a loop, the else statement checks if a break statement was used.

If a break statement is used, the loop is terminated and the else block is not going to be executed.

If a break statement is not used, the loop runs all the way through and triggers the else block.

In other words, a loop that does not have a break statement will always run the else block.

By the way, if you don’t know how the break statement works, the next section is a quick primer. If you are familiar with this stuff, feel free to skip to the next section.

The ‘break’ Statement in Python

In Python, you can control the flow of a loop.

Normally, the loop body is executed line by line from top to bottom.

But you can change this by using one of Python’s built-in control flow statements:

The continue statement. Skips the rest of the current iteration and starts the next one.

The break statement. Terminates the loop altogether.

These statements can be used in both for and while loops.

Let’s see an example of the continue statement by printing all the even numbers in a list of numbers:

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] for number in numbers: if number % 2 != 0: continue print(number)

Output:

2 4 6 8 10

Here the if statement checks if the number is odd. If it is, the continue statement is used to skip printing the number.

Sometimes you also might want to terminate the whole loop before it finishes.

This is useful in situations where you want to avoid excess looping, such as when you find a target value.

To terminate a loop in Python, use the break statement.

When the loop encounters a break statement, it terminates the loop and continues executing the program from the next line.

For example, let’s search for a target number and exit the loop if the number is found:

numbers = [1, 5, 43, 2, 7, 9, 19, 10] target = 43 for number in numbers: print(number) if number == target: print("Target found, escaping the loop") break

Output:

1 5 43 Target found, escaping the loop

As you can see from the output, the loop was terminated once the target number was found.

Here it makes sense to stop the loop because why continue searching for something you already found?

This was a quick intro to the control flow statements and especially the break statement in Python.

Let’s continue with the topic of the day, that is, how and why to use the else block in a loop in Python.

First, let’s look at how the else statement works in a for loop.

The ‘else’ Statement in a For Loop

In Python, you can place an else statement into a for loop.

To do this, insert the else keyword into the same indentation level as the for keyword.

for var in iterable: # loop actions else: # actions after loop

The else statement works such that if a break statement is not used, the else block will run.

Let me show you an example.

Let’s use a for loop to iterate over a list of numbers in search of a target number. If the target number is found, let’s break the loop. If not, let’s print a message.

For example:

numbers = [1, 5, 43, 2, 7, 9, 19, 10] target = 100 for number in numbers: if number == target: print("Target found, escaping the loop") break else: print("Target not found. The loop ran through all the numbers.")

Output:

Target not found. The loop ran through all the numbers.

Here the else block is executed because the target number was not found and the break statement was not used.

Let’s see another example.

If you specify an else block to a for loop that does not have a break statement, the else block is always executed:

for i in range(5): print(i) else: print("Loop completed")

Output:

0 1 2 3 4 Loop completed

Using the else block this way makes no sense because it will always run. Here you could display the message right after the loop without using an else block.

for i in range(5): print(i) print("Loop completed")

It only makes sense to specify an else block into a loop to perform actions if the loop was not stopped by a break statement.

The next chapter teaches you how to use the else block in a while loop. TLDR; the idea is exactly the same as using it in the for loops.

The ‘else’ Statement in a While Loop

In Python, you can also insert an else statement into a while loop.

To do this, add the else keyword into the same indentation level as the while keyword.

while condition: # loop actions else: # actions after loop

Identical to the for loop example, if a break statement is not used in a while loop, the else block will run.

For example, let’s search for a target number using a while loop:

numbers = [1, 5, 43, 2, 7, 9, 19, 10] target = 100 i = 0 while i < len(numbers): if numbers[i] == target: print("Target found, escaping the loop") break i += 1 else: print("Target not found. The loop ran through all the numbers.")

Output:

Target not found. The loop ran through all the numbers.

Because the target number was not found, the break statement was never used. Thus, the else block was executed.

Last but not least, let’s briefly discuss the inconvenience of this.

Why ‘else’?

Now you understand how to use the else block in loops in Python.

But isn’t it confusing?

Most likely you did not expect the else block to work that way.

Syntactically, it is not clear that the else block only runs if the loop was not terminated by a break statement.

Perhaps Python authors did not want to create a new keyword for such a situation, even though they probably should.

For instance, it would be much cleaner if one could use something like nobreak instead of else in a loop.

Conclusion

In Python, you can place an else statement after a loop.

This is executed if the break statement was not used in the loop. In other words, if the loop completes without interruption.

If a break statement is used, the else block will not run.

This is counterintuitive because else is not the best keyword to describe this. The authors of Python could have done a better job by introducing a new keyword such that nobreak.

Thanks for reading.

Happy coding!

Further Reading

Python Interview Questions

All Reserved Keywords in Python

You're reading Python For…Else: The ‘Else’ Statement In Loops

Python Conditional Statements: If…Else, Elif & Switch Case

What are Conditional Statements in Python?

Conditional Statement in Python perform different computations or actions depending on whether a specific Boolean constraint evaluates to true or false. Conditional statements are handled by IF statements in Python.

What is Python If Statement?

Python if Statement is used for decision-making operations. It contains a body of code which runs only when the condition given in the if statement is true. If the condition is false, then the optional else statement runs which contains some code for the else condition.

When you want to justify one condition while the other condition is not true, then you use Python if else statement.

Python if Statement Syntax:

if expression Statement else Statement

Python if…else Flowchart

Let’s see an example of Python if else Statement:

# #Example file for working with conditional statement # def main(): x,y =2,8 if(x < y): st= "x is less than y" print(st) if __name__ == "__main__": main()

Code Line 5: We define two variables x, y = 2, 8

Code Line 7: The if Statement in Python checks for condition x<y which is True in this case

Code Line 8: The variable st is set to “x is less than y.”

Code Line 9: The line print st will output the value of variable st which is “x is less than y”,

What happen when “if condition” does not meet

In this step, we will see what happens when if condition in Python does not meet.

Code Line 5: We define two variables x, y = 8, 4

Code Line 7: The if Statement in Python checks for condition x<y which is False in this case

Code Line 8: The variable st is NOT set to “x is less than y.”

Code Line 9: The line print st – is trying to print the value of a variable that was never declared. Hence, we get an error.

How to use “else condition”

The “else condition” is usually used when you have to judge one statement on the basis of other. If one condition goes wrong, then there should be another condition that should justify the statement or logic.

Example:

# #Example file for working with conditional statement # def main(): x,y =8,4 if(x < y): st= "x is less than y" else: st= "x is greater than y" print (st) if __name__ == "__main__": main()

Code Line 5: We define two variables x, y = 8, 4

Code Line 7: The if Statement in Python checks for condition x<y which is False in this case

Code Line 9: The flow of program control goes to else condition

Code Line 10: The variable st is set to “x is greater than y.”

Code Line 11: The line print st will output the value of variable st which is “x is greater than y”,

When “else condition” does not work

There might be many instances when your “else condition” won’t give you the desired result. It will print out the wrong result as there is a mistake in program logic. In most cases, this happens when you have to justify more than two statement or condition in a program.

An example will better help you to understand this concept.

Here both the variables are same (8,8) and the program output is “x is greater than y”, which is WRONG. This is because it checks the first condition (if condition in Python), and if it fails, then it prints out the second condition (else condition) as default. In next step, we will see how we can correct this error.

# #Example file for working with conditional statement # def main(): x,y =8,8 if(x < y): st= "x is less than y" else: st= "x is greater than y" print(st) if __name__ == "__main__": main()

How to use “elif” condition

To correct the previous error made by “else condition”, we can use “elif” statement. By using “elif” condition, you are telling the program to print out the third condition or possibility when the other condition goes wrong or incorrect.

Example

# #Example file for working with conditional statement # def main(): x,y =8,8 if(x < y): st= "x is less than y" elif (x == y): st= "x is same as y" else: st="x is greater than y" print(st) if __name__ == "__main__": main()

Code Line 5: We define two variables x, y = 8, 8

Code Line 7: The if Statement checks for condition x<y which is False in this case

Code Line 10: The flow of program control goes to the elseif condition. It checks whether x==y which is true

Code Line 11: The variable st is set to “x is same as y.”

Code Line 15: The flow of program control exits the if Statement (it will not get to the else Statement). And print the variable st. The output is “x is same as y” which is correct

How to execute conditional statement with minimal code

In this step, we will see how we can condense out the conditional statement. Instead of executing code for each condition separately, we can use them with a single code.

Syntax

A If B else C

Example:

def main(): x,y = 10,8 st = "x is less than y" if (x < y) else "x is greater than or equal to y" print(st) if __name__ == "__main__": main()

Code Line 2: We define two variables x, y = 10, 8

Code Line 4: Prints the value of st and gives the correct output

Instead of writing long code for conditional statements, Python gives you the freedom to write code in a short and concise way.

Python Nested if Statement

Following example demonstrates nested if Statement Python

total = 100 #country = "US" country = "AU" if country == "US": if total <= 50: print("Shipping Cost is $50") elif total <= 100: print("Shipping Cost is $25") elif total <= 150: print("Shipping Costs $5") else: print("FREE") if country == "AU": if total <= 50: print("Shipping Cost is $100") else: print("FREE") Switch Case Statement in Python

What is Switch statement?

A switch statement is a multiway branch statement that compares the value of a variable to the values specified in case statements.

Python language doesn’t have a switch statement.

Python uses dictionary mapping to implement Switch Case in Python

Example

function(argument){ switch(argument) { case 0: return "This is Case Zero"; case 1: return " This is Case One"; case 2: return " This is Case Two "; default: return "nothing"; }; };

For the above Switch case in Python

def SwitchExample(argument): switcher = { 0: " This is Case Zero ", 1: " This is Case One ", 2: " This is Case Two ", } return switcher.get(argument, "nothing") if __name__ == "__main__": argument = 1 print (SwitchExample(argument))

Python 2 Example

Above codes are Python 3 examples, If you want to run in Python 2 please consider following code.

# If Statement #Example file for working with conditional statement # def main(): x,y =2,8 if(x < y): st= "x is less than y" print st if __name__ == "__main__": main() # How to use "else condition" #Example file for working with conditional statement # def main(): x,y =8,4 if(x < y): st= "x is less than y" else: st= "x is greater than y" print st if __name__ == "__main__": main() # When "else condition" does not work #Example file for working with conditional statement # def main(): x,y =8,8 if(x < y): st= "x is less than y" else: st= "x is greater than y" print st if __name__ == "__main__": main() # How to use "elif" condition #Example file for working with conditional statement # def main(): x,y =8,8 if(x < y): st= "x is less than y" elif (x == y): st= "x is same as y" else: st="x is greater than y" print st if __name__ == "__main__": main() # How to execute conditional statement with minimal code def main(): x,y = 10,8 st = "x is less than y" if (x < y) else "x is greater than or equal to y" print st if __name__ == "__main__": main() # Nested IF Statement total = 100 #country = "US" country = "AU" if country == "US": if total <= 50: print "Shipping Cost is $50" elif total <= 100: print "Shipping Cost is $25" elif total <= 150: print "Shipping Costs $5" else: print "FREE" if country == "AU": if total <= 50: print "Shipping Cost is $100" else: print "FREE" #Switch Statement def SwitchExample(argument): switcher = { 0: " This is Case Zero ", 1: " This is Case One ", 2: " This is Case Two ", } return switcher.get(argument, "nothing") if __name__ == "__main__": argument = 1 print SwitchExample(argument) Summary

A conditional statement in Python is handled by if statements and we saw various other ways we can use conditional statements like Python if else over here.

“if condition” – It is used when you need to print out the result when one of the conditions is true or false.

“else condition”- it is used when you want to print out the statement when your one condition fails to meet the requirement

“elif condition” – It is used when you have third possibility as the outcome. You can use multiple elif conditions to check for 4th,5th,6th possibilities in your code

We can use minimal code to execute conditional statements by declaring all condition in single statement to run the code

Python If Statement can be nested

Nested If Statement In Python

Introduction to Nested IF Statement in Python

Programming has surely come a long way from a simple “Hello World” program to all the modern day’s complex programs. With time new features got added to programming to cater to various needs.

Start Your Free Software Development Course

Web development, programming languages, Software testing & others

So we need to introduce some sort of Decision making capability to our programs to make them more robust.

Let us suppose we have a program in which we input a number from the user and check whether it is an even number or an odd number. It is a classic example of using a conditional statement. The following flowchart would help depict it more clearly:-

Examples of Conditional Statements in Python

This is an example of an elementary conditional statement for finding whether a number is even or not.

The following are the different kinds of Conditional Statements in Python: –

if statement

if-else statement

else-if statement

nested if statement

switch statement

In this article, we would focus mainly on Nested If Statements, for which we would have a little introduction of If Statements, and then we would jump to the main topic.

1. If Statements

Syntax: –

Let us look into the details of the syntax of the if-statement.

The most important component is the “if” keyword, which helps us identify an expression to be a conditional statement.

expr: – This signifies the condition, the fulfillment of which would execute the below statement. The expr is basically a Python statement that results in a Boolean value (True or False). The statement for the particular expr will get executed only if the value for the expr is True.

statement: – This is the final part of the if-statement, which is the path along which the program must flow if the expr is True.

This is just a recap of the if-statement in Python as the nested if is an extension of the same.

2. Nested If Statements

A nested if is an if statement that is the target of a previous if statement. Let us look at the syntax of a nested if-statement.

# Executes statement1 when expr1 is True # Executes statement2 when expr2 is True # Inner if-block ends here # Outer if-block ends here

Let us look at the flow chart of nested if-statement to have a better understanding of it: –

In the following example, we implement the nested if-statement on a program where the user inputs a number and checks different conditions with regards to that number. Though the program is very simple, the only intention is to discuss the nested if-statements’ flow.

Code: 

a = 10 print("Inside initial if") print("Number is greater than 5") print("Inside first nested if") print("Number is greater than or equal to 10") print("Inside second nested if") print("Number is greater than or equal to 15") print("Outside second nested if") print("Outside second nested if") print("Outside initial if")

Output: –

The nested if must be properly indented, the failure of which results in Indentation Error as follows: –

a = 10 print("Greater than 7")

Output: –

Colon (:) must be follow all the ifs in the nested if-statements; otherwise, invalid syntax error would occur as follows:

Code:

a = 10 print("Greater than 7")

Output: 

Conclusion

It is finally time to draw closure to this article. In this article, we learnt the need for Conditional Statements in programming, touched upon the basics of if-statement with its syntax. Lastly, we discussed about nested if-statements in Python in details. I hope by now you guys are able to appreciate the usage of nested if-statements in Python. Now it is time to write your own Python program implementing the concepts learnt in this article.

Recommended Articles

This is a guide to the Nested IF Statement in Python. Here we discuss the Nested IF Statement in Python detailed discussion with examples and its Code Implementation. You can also go through our other suggested articles to learn more –

Python “Finally” Statement: An Ultimate Guide (With Examples)

In Python, the finally statement is helpful with error handling to ensure code executes.

For example, here the something_else() call does not run because it is not in an finally block:

try: something() except: return None something_else() # This does not get executed

But by placing it inside a finally block, it gets executed no matter what:

try: something() except: return None finally: something_else() # Always gets executed

This is a comprehensive guide to the finally statement in Python. You’ll learn what the finally keyword does and how you can use it in error handling. Besides, you will learn how the finally keyword works with continue and break statements.

Early Return with “finally” Statement

If your error handling code returns a value in the except block, the code that comes after that does not execute.

For example, let’s return a value from the function if an exception occurs.

def without_finally(): try: print(x) except: print("There was an error") return None print("Yay") without_finally()

As we tried to print an undefined value x, there was an exception. Thus the function returned a value and print("Yay") was never run.

There was an error

As you can see, "Yay" does not get printed out because the function exits before.

But if we place the print function call into a finally block, it indeed gets executed.

def with_finally(): try: print(x) except: print("There was an error") return None finally: print("Yay") with_finally()

Output:

There was an error Yay

So even though we return from the function inside the except block, the code in the finally block runs.

This is useful if you want to run cleanup code before exiting.

For example, you could close opened files in the finally block.

An Unexpected Error

In error handling, we expect certain types of errors in the except block(s).

But sometimes the error could be something that the except block is not prepared for.

When this happens, the finally block still gets executed.

To demonstrate, let’s try to write to a file. The code inside the try block throws an error unrelated to file writing:

file = open("example.txt", "w") try: print(x) file.write("Test") print("Writing to file.") except IOError: print("Could not write to file.") else: print("Write successful.") finally: file.close() print("File closed.")

Output:

File closed. Traceback (most recent call last): print(x) NameError: name 'x' is not defined

The except block did not run because we got a different kind of error than expected.

But still, the finally block was executed before propagating the error to the caller.

This would have been different without the finally block:

file = open("example.txt", "w") try: print(x) file.write("Test") print("Writing to file.") except IOError: print("Could not write to file.") else: print("Write successful.") file.close() print("File closed.")

Output:

Traceback (most recent call last): print(x) NameError: name 'x' is not defined

As you can see, the file would not be closed, and the final message would not have been logged.

Continue with “finally” Statement

In Python, the continue statement skips the “rest of the iteration” in a loop and continues to the next one.

If you use a continue statement in an error-handling code in a loop, any code after continue does not get executed.

For example:

def without_finally(): for i in range(5): try: print(x) except: print("There was an error") continue print("Yay") without_finally()

Output:

There was an error There was an error There was an error There was an error There was an error

Here “Yay” does not get printed out.

This is because the continue statement already jumped to the next iteration.

You can fix this by using the finally statement:

def with_finally(): for i in range(5): try: print(x) except: print("There was an error") continue finally: print("Yay") with_finally()

Output:

There was an error Yay There was an error Yay There was an error Yay There was an error Yay There was an error Yay Break with “finally” Statement

The break statement exits a loop in Python.

If you do error handling in a loop and you break the loop, the code after break will not be executed.

For example, let’s break a loop on an exception:

def without_finally(): for i in range(5): try: print(x) except: print("There was an error") break print("Yay") without_finally()

Output:

There was an error

Here, the “Yay” was not printed into the console, because the loop was escaped beforehand.

Let’s use the finally block to ensure the “Yay” gets printed:

def with_finally(): for i in range(5): try: print(x) except: print("There was an error") break finally: print("Yay") with_finally()

Output:

There was an error Yay Except Throws Another Exception

If you are not using finally statement, and there is an error in the except block, everything after that is not going to be executed.

For example:

def without_finally(): try: print(x) except: print("There was an error") print(y) print("Yay") without_finally()

Output:

There was an error Traceback (most recent call last): File "example.py", line 3, in without_finally print(x) NameError: name 'x' is not defined During handling of the above exception, another exception occurred: Traceback (most recent call last): without_finally() File "example.py", line 6, in without_finally print(y) NameError: name 'y' is not defined

This only prints “There was an error” before throwing the error. It does not print “Yay” after the error handling structure.

But if you used a finally block, the print("Yay") would also be executed.

def with_finally(): try: print(x) except: print("There was an error") print(y) finally: print("Yay") with_finally()

Output:

There was an error Yay Traceback (most recent call last): File "example.py", line 3, in with_finally print(x) NameError: name 'x' is not defined During handling of the above exception, another exception occurred: Traceback (most recent call last): with_finally() File "example.py", line 6, in with_finally print(y) NameError: name 'y' is not defined Conclusion

Today you learned what is the point of the finally statement in Python error handling.

The finally statement is always executed no matter what. This is useful if you need to run cleanup code regardless of what happens.

For example, as a cleanup, you should always close a file no matter what.

I hope you find it useful.

Happy coding.

Further Reading

Top 10 Python Compilers For Python Developers In 2023

Here are the top 10 python compilers for python developers in 2023 selected by experts.

A python compiler is a program that translates a high-level programming language into a lower-level language so that the assembly can understand and interpret the logical inputs.

Both online and offline python compilers for python developers are available.

Coding, designing, deploying, and troubleshooting development projects, typically on the server-side (or back end), fall under the purview of a Python developer. However, they might also assist businesses with their technological framework.  For beginners, there are many Python compilers in 2023 but the top 10 Python compilers are as follows:

Programiz:

Programiz is free and open-source, meaning that it doesn’t cost anything to get started, making it ideal for beginners. Being immersive, extensible, and flexible, it is an interpreted language of a high level. It has a large community and a large library to continue improving its utility for programmers.

Pydev:

Refactoring, debugging, code analysis, and other powerful specifications are available in Pydev. Unittest integration, PyLint, and other features are all supported by Pydev.

Black-formatted virtual environments and Mypy are made possible with Pydev.

Code folding, syntax highlighting, and support for a variety of other programming languages are all made possible by Pydev. It is compatible with the Django Framework, Jython, and other programming languages.

PyCharm:

Over a thousand plugins are supported by PyCharm. We can quickly switch between multiple files. The plugin can be written by developers on their own.

Sublime Text:

It has a “Goto Anything” feature, which allows us to move the cursor to any location we choose. Multiple lines and words can be chosen in sublime text. Its preferences can be altered to meet the needs of a particular project. Its free version is accessible to all. It has a plugin that can highlight text and is excellent for debugging. It supports finds and replaces features more effectively than others. We can work on multiple projects simultaneously without getting lost. It keeps recommending correct syntax.

Thonny:

For each function call, a separate window is displayed. The debugger is extremely user-friendly. The F5, F6, and F7 keys are used. It depicts the function calls and emphasizes the coding error. The code is completed automatically by it. A simple user interface makes it easy to use. Thonny is the best IDE for novices. It takes care of the coding problems caused by other interpreters.

Visual Studio Code:

Python coding, debugging, and other activities are supported by Visual Studio Code, which is light and easy to use. There are two free and paid versions of Visual Studio Code. Advanced features are included in the paid version. It supports a variety of programming languages and has plugins built in. It can be customized to meet individual requirements. It quickly finishes and finds the code.

Jupyter Notebook:

Markdowns are supported in Jupyter notebook, and you can include HTML code in videos and images. It makes editing simple and easy. It is ideal for people who are just starting in the field of data science. We can use data visualization libraries like Seaborn and Matplotlib to show where the code is in the graphs in the same document. The final work can be exported in a variety of formats.

Vim:

Vim has a very small footprint on memory. It is the hub of command. With just a few commands, we can handle intricate text and related tasks. It stores its configuration in a simple computer file and is extremely configurable. For Vim, number of plug-ins are available. By utilizing these plug-ins, its usability will be enhanced. There will be multiple windows on the screen for the exploitation feature. It also supports multiple buffers in multiple windows. It has multiple tabs that allow figures to be displayed on multiple files. It has options for recording that make it possible to continuously record and play Vim commands.

Atom:

Spyder:

Using The Append() Method In Python

One of the essential features of Python is the ability to manipulate lists, which are collections of items of the same or different data types such as strings, integers, or even other lists. In this article, we will explore the append() method, which is a built-in function in Python that allows you to add an item to the end of a list.

What is Python Append?

The append() method is a list method in Python that adds an item to the end of a list. The syntax of the append() method is as follows:

list.append(item)

Here, list is the name of the list to which you want to add an item, and item is the value that you want to append. The append() method modifies the original list and returns None. It does not create a new list.

How to Use Python Append?

Let’s look at some examples of how to use the append() method in Python.

Example 1: Adding an Integer to a List numbers = [1, 2, 3, 4] numbers.append(5) print(numbers)

Output:

[1, 2, 3, 4, 5]

In this example, we have a list of integers called numbers. We use the append() method to add the integer 5 to the end of the list. The print() function is used to display the modified list.

Example 2: Adding a String to a List fruits = ['apple', 'banana', 'cherry'] fruits.append('orange') print(fruits)

Output:

['apple', 'banana', 'cherry', 'orange']

In this example, we have a list of strings called fruits. We use the append() method to add the string ‘orange’ to the end of the list. The print() function is used to display the modified list.

Example 3: Adding a List to a List list1 = [1, 2, 3] list2 = [4, 5, 6] list1.append(list2) print(list1)

Output:

[1, 2, 3, [4, 5, 6]]

In this example, we have two lists called list1 and list2. We use the append() method to add list2 to the end of list1. As a result, list1 becomes a nested list that contains both the original elements and the new list.

Example 4: Adding Multiple Items to a List colors = ['red', 'green', 'blue'] colors.append('yellow', 'purple') print(colors)

Output:

TypeError: append() takes exactly one argument (2 given)

In this example, we have a list of strings called colors. We attempt to add two strings, ‘yellow’ and ‘purple’, to the end of the list using the append() method. However, this results in a TypeError because the append() method can only accept one argument at a time.

Example 5: Using Append in a Loop numbers = [] for i in range(1, 6): numbers.append(i) print(numbers)

Output:

[1, 2, 3, 4, 5]

In this example, we create an empty list called numbers. We use a for loop to iterate from 1 to 5 and append each integer to the end of the list. The print() function is used to display the modified list.

Related Concepts and Methods

There are several other list methods in Python that are related to the append() method and can be useful in various scenarios.

extend(iterable)

This method can be used to append all the elements of an iterable to a list. For example:

list1 = [1, 2, 3] list2 = [4, 5, 6] list1.extend(list2) print(list1)

Output:

[1, 2, 3, 4, 5, 6] insert(index, item)

This method can be used to insert an item at a specific position in a list. For example:

numbers = [1, 2, 3, 4] numbers.insert(2, 2.5) print(numbers)

Output:

[1, 2, 2.5, 3, 4] remove(item)

This method can be used to remove the first occurrence of an item from a list. For example:

colors = ['red', 'green', 'blue', 'green'] colors.remove('green') print(colors)

Output:

['red', 'blue', 'green'] pop(index)

This method can be used to remove and return the item at a specific position in a list. If no index is specified, it removes and returns the last item in the list. For example:

numbers = [1, 2, 3, 4] last_number = numbers.pop() print(last_number) print(numbers)

Output:

4 [1, 2, 3]

By understanding these related concepts and methods, you can expand your knowledge of list manipulation in Python and write more efficient and effective code.

Conclusion

The append() method in Python is a simple yet powerful way to add an item to the end of a list. By using this method, you can modify lists dynamically and create complex data structures that can be used in a variety of applications. Whether you are a beginner or an experienced Python programmer, understanding the append() method and its related concepts is an essential skill that can help you write better code and solve more complex problems.

Update the detailed information about Python For…Else: The ‘Else’ Statement In Loops on the Moimoishop.com website. We hope the article's content will meet your needs, and we will regularly update the information to provide you with the fastest and most accurate information. Have a great day!