# Converting Letters to Numbers and Vice Versa in Python: A Beginner’s Guide

## Python is a widely known programming language

because of its syntax, readability, and flexibility. One of the most useful features of Python is its ability to convert letters to numbers and vice versa.

## To convert a letter to a number in Python, we can use the “ord()” function. The “ord()” function returns the Unicode code point of the character.

In other words, it returns the integer representation of the Unicode code of the character. For example, let’s convert the letter “A” to a number:

``print(ord('A'))``

## The output will be:

``65``

As you can see, the “ord()” function returns the Unicode code point of the character. The Unicode code point of “A” is 65.

## Getting a one-based result instead of the Unicode code point of the character

If you want to get a one-based result instead of the Unicode code point of the character, you can subtract ‘A’ or ‘a’ (depending on if the letter is uppercase or lowercase) from the result of the “ord()” function. For example, let’s convert the letter “a” to a one-based result:

``print(ord('a') - ord('a') + 1)``

## The output will be:

``1``

As you can see, we first used the “ord()” function to get the Unicode code point of the character “a”. We then subtracted ord(‘a’) from ord(‘a’) and added 1 to get a one-based result.

## For example, let’s convert the number 65 to a letter:

``print(chr(65))``

## The output will be:

``A``

As you can see, the “chr()” function returns the corresponding character of the Unicode code point of 65, which is “A”.

## To convert a number to a lowercase or uppercase letter in Python, we can use the “ord()” and “chr()” functions together.

We can add or subtract a specific value from the result of the “ord()” function depending on whether we want to convert the number to a lowercase or uppercase letter. For example, let’s convert the number 97 to a lowercase letter:

``print(chr(ord('a') + 97 - 97))``

## The output will be:

``a``

As you can see, we first used the “ord()” function to get the Unicode code point of ‘a’. We then added 97 to 97 and used the “chr()” function to get the corresponding character of the resulting Unicode code point.

In conclusion, converting letters to numbers and vice versa is an essential feature of Python. With the help of the “ord()” and “chr()” functions, Python makes it effortless to convert between these two data types.

Whether you’re working with text data or creating a game that requires character input, the knowledge you’ve gained in this article will undoubtedly come in handy for your next Python project.

## One of the most popular and concise ways to convert all letters in a string to numbers is by using a list comprehension.

A list comprehension creates a new list from an existing one, and it’s an efficient way to process elements in lists. Therefore, we can use a list comprehension to loop through each character of the string and convert them to numbers.

Here’s an example of how we can convert all letters in a string to numbers:

``````string = 'hello world'
result = [ord(i) for i in string]

print(result)``````

## The output will be:

``[104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]``

In this example, we loop through each character of the string using a list comprehension. The “ord()” function returns the Unicode code point of each character, and we append the result to a new list.

## Getting a one-based result instead of the Unicode code point of the character

If you want to get a one-based result instead of the Unicode code point of the character, you can subtract ‘A’ or ‘a’ (depending on whether the letter is uppercase or lowercase) from the result of the “ord()” function, as mentioned earlier. Here’s an example of how we can get a one-based result instead of the Unicode code point of the character:

``````string = 'Hello World'
result = [ord(i) - ord('a') + 1 if i.islower() else ord(i) - ord('A') + 1 if i.isupper() else '' for i in string]

print(result)``````

## The output will be:

``[8, 5, 12, 12, 15, '', 23, 15, 18, 12, 4]``

In this example, we used the list comprehension to loop through the string and check whether each character is lowercase or uppercase. If the character is lowercase, we subtract the result of “ord(‘a’)” from the result of the “ord()” function and added one to get the one-based result.

If the character is uppercase, we subtract the result of “ord(‘A’)” from the result of the “ord()” function and added one to get the one-based result. If the character is neither lowercase nor uppercase, we added an empty string to the list.

## Another way to convert all letters in a string to numbers is by using a for loop and appending the results to a new list. This method is more explicit than using a list comprehension, and it might be easier to understand for beginners.

Here’s an example of how we can convert all letters in a string to numbers using a for loop:

``````string = 'hello world'
result = []
for i in string:
result.append(ord(i))

print(result)``````

## The output will be:

``[104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]``

In this example, we initialized an empty list called “result”. Then, we looped through each character of the string using a for loop and used the “ord()” function to convert the character to a number.

Finally, we appended the result to the “result” list.

Learning how to convert letters to numbers in Python is a fundamental concept, especially in data manipulation and encryption techniques. Here are some useful resources that can help you learn more about the topic:

1. Python String Methods: https://www.w3schools.com/python/python_strings_methods.asp

2. Unicode HOWTO: https://docs.python.org/3/howto/unicode.html

3. Python List Comprehensions: https://www.pythonforbeginners.com/basics/list-comprehensions-in-python

4. 5 Reasons You Should Learn Python: https://www.codingdojo.com/blog/5-reasons-learn-python

In conclusion, converting all letters in a string to numbers may seem like a complicated task at first, but it’s a skill that every Python developer should master.

With the knowledge and techniques provided in this article, you’re now well-equipped to handle this task with ease. Moreover, with the resources provided, you can take your skills to the next level and learn more about the vast capabilities of Python.

In conclusion, converting letters to numbers and vice versa using Python is a crucial skill for any programmer, especially in data manipulation and encryption techniques. Converting all letters in a string to numbers can be achieved by using list comprehensions or a for loop.

By using the “ord()” and “chr()” functions, Python makes it easy to convert between these two data types. Remember to use list comprehensions for a concise and efficient method, or use a for loop for a more explicit approach.

Take advantage of the included resources to develop further on the topic and unlock the vast capabilities of Python. By mastering this skill, you’ll enhance your programming capabilities and be able to handle more complex tasks with ease.