Adventures in Machine Learning

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

Python is

a widely known progr

amming l

angu

age bec

ause of its synt

ax, re

ad

ability,

and flexibility. One of the most useful fe

atures of Python is its

ability to convert letters to numbers

and vice vers

a.

In this

article, we will explore how you c

an convert letters to numbers in Python

and how you c

an convert numbers to letters in Python.

Convert letters to numbers in Python

To convert

a letter to

a number in Python, we c

an use the “ord()” function. The “ord()” function returns the Unicode code point of the ch

ar

acter.

In other words, it returns the integer represent

ation of the Unicode code of the ch

ar

acter. For ex

ample, let’s convert the letter “

A” to

a number:

“`

print(ord(‘

A’))

“`

The output will be:

“`

65

“`

As you c

an see, the “ord()” function returns the Unicode code point of the ch

ar

acter. The Unicode code point of “

A” is

65.

Getting

a one-b

ased result inste

ad of the Unicode code point of the ch

ar

acter

If you w

ant to get

a one-b

ased result inste

ad of the Unicode code point of the ch

ar

acter, you c

an subtr

act ‘

A’ or ‘

a’ (depending on if the letter is upperc

ase or lowerc

ase) from the result of the “ord()” function. For ex

ample, let’s convert the letter “

a” to

a one-b

ased result:

“`

print(ord(‘

a’) – ord(‘

a’) +

1)

“`

The output will be:

“`

1

“`

As you c

an see, we first used the “ord()” function to get the Unicode code point of the ch

ar

acter “

a”. We then subtr

acted ord(‘

a’) from ord(‘

a’)

and

added

1 to get

a one-b

ased result.

Convert numbers to letters in Python

To convert

a number to

a letter in Python, we c

an use the “chr()” function. The “chr()” function returns the corresponding ch

ar

acter (

as

a string) of the given Unicode code point.

For ex

ample, let’s convert the number

65 to

a letter:

“`

print(chr(

65))

“`

The output will be:

“`

A

“`

As you c

an see, the “chr()” function returns the corresponding ch

ar

acter of the Unicode code point of

65, which is “

A”. Using ord()

and chr() functions to convert

a number to

a lowerc

ase/upperc

ase letter

To convert

a number to

a lowerc

ase or upperc

ase letter in Python, we c

an use the “ord()”

and “chr()” functions together.

We c

an

add or subtr

act

a specific v

alue from the result of the “ord()” function depending on whether we w

ant to convert the number to

a lowerc

ase or upperc

ase letter. For ex

ample, let’s convert the number 97 to

a lowerc

ase letter:

“`

print(chr(ord(‘

a’) + 97 – 97))

“`

The output will be:

“`

a

“`

As you c

an 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 ch

ar

acter of the resulting Unicode code point.

In conclusion, converting letters to numbers

and vice vers

a is

an essenti

al fe

ature of Python. With the help of the “ord()”

and “chr()” functions, Python m

akes it effortless to convert between these two d

at

a types.

Whether you’re working with text d

at

a or cre

ating

a g

ame th

at requires ch

ar

acter input, the knowledge you’ve g

ained in this

article will undoubtedly come in h

andy for your next Python project.

As

a Python developer, you might f

ace situ

ations where you need to convert the entire string of letters to numbers. For inst

ance, when you’re working with encryption techniques, it’s common to convert letters to numbers.

In this

article, we’ll discuss two different w

ays to convert

all letters in

a string to numbers. Convert

all letters in

a string to numbers using

a list comprehension

One of the most popul

ar

and concise w

ays to convert

all letters in

a string to numbers is by using

a list comprehension.

A list comprehension cre

ates

a new list from

an existing one,

and it’s

an efficient w

ay to process elements in lists. Therefore, we c

an use

a list comprehension to loop through e

ach ch

ar

acter of the string

and convert them to numbers.

Here’s

an ex

ample of how we c

an 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,

10

1,

108,

108,

1

1

1, 32,

1

19,

1

1

1,

1

14,

108,

100]

“`

In this ex

ample, we loop through e

ach ch

ar

acter of the string using

a list comprehension. The “ord()” function returns the Unicode code point of e

ach ch

ar

acter,

and we

append the result to

a new list.

Getting

a one-b

ased result inste

ad of the Unicode code point of the ch

ar

acter

If you w

ant to get

a one-b

ased result inste

ad of the Unicode code point of the ch

ar

acter, you c

an subtr

act ‘

A’ or ‘

a’ (depending on whether the letter is upperc

ase or lowerc

ase) from the result of the “ord()” function,

as mentioned e

arlier. Here’s

an ex

ample of how we c

an get

a one-b

ased result inste

ad of the Unicode code point of the ch

ar

acter:

“`

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 ex

ample, we used the list comprehension to loop through the string

and check whether e

ach ch

ar

acter is lowerc

ase or upperc

ase. If the ch

ar

acter is lowerc

ase, we subtr

act the result of “ord(‘

a’)” from the result of the “ord()” function

and

added one to get the one-b

ased result.

If the ch

ar

acter is upperc

ase, we subtr

act the result of “ord(‘

A’)” from the result of the “ord()” function

and

added one to get the one-b

ased result. If the ch

ar

acter is neither lowerc

ase nor upperc

ase, we

added

an empty string to the list.

Convert

all letters in

a string to numbers using

a for loop

and

appending results to

a new list

Another w

ay 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 th

an using

a list comprehension,

and it might be e

asier to underst

and for beginners.

Here’s

an ex

ample of how we c

an 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,

10

1,

108,

108,

1

1

1, 32,

1

19,

1

1

1,

1

14,

108,

100]

“`

In this ex

ample, we initi

alized

an empty list c

alled “result”. Then, we looped through e

ach ch

ar

acter of the string using

a for loop

and used the “ord()” function to convert the ch

ar

acter to

a number.

Fin

ally, we

appended the result to the “result” list.

Addition

al Resources

Le

arning how to convert letters to numbers in Python is

a fund

ament

al concept, especi

ally in d

at

a m

anipul

ation

and encryption techniques. Here

are some useful resources th

at c

an help you le

arn 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/b

asics/list-comprehensions-in-python

4. 5 Re

asons You Should Le

arn Python: https://www.codingdojo.com/blog/5-re

asons-le

arn-python

In conclusion, converting

all letters in

a string to numbers m

ay seem like

a complic

ated t

ask

at first, but it’s

a skill th

at every Python developer should m

aster.

With the knowledge

and techniques provided in this

article, you’re now well-equipped to h

andle this t

ask with e

ase. Moreover, with the resources provided, you c

an t

ake your skills to the next level

and le

arn more

about the v

ast c

ap

abilities of Python.

In conclusion, converting letters to numbers

and vice vers

a using Python is

a cruci

al skill for

any progr

ammer, especi

ally in d

at

a m

anipul

ation

and encryption techniques. Converting

all letters in

a string to numbers c

an be

achieved by using list comprehensions or

a for loop.

By using the “ord()”

and “chr()” functions, Python m

akes it e

asy to convert between these two d

at

a types. Remember to use list comprehensions for

a concise

and efficient method, or use

a for loop for

a more explicit

appro

ach.

T

ake

adv

ant

age of the included resources to develop further on the topic

and unlock the v

ast c

ap

abilities of Python. By m

astering this skill, you’ll enh

ance your progr

amming c

ap

abilities

and be

able to h

andle more complex t

asks with e

ase.