String Formatting with Python-f-String, and why you should start using it

So, What is String Formatting?

String Formatting (sometimes also referred as “String Interpolation”) is a technique for embedding or inserting variables into placeholders in a Python String object.

Three ways to format a String in Python:

1. Old school %s String Formatting

2. A better string formatting: String.format()

3. f”string” method - why it’s the best for String formatting in Python compared to .format() and %s

name = "Frank"
age = 24
profession = "Python Dev"
language = "Python"

person = dict(name="Frank", age=24,
              profession="Python Dev", language="Python")

1. %s string formatting

print("My name is %s and I'm a %s. I'm currently being %s and my favourite language is %s" \
% (name, profession, age, language))

My name is Frank and I'm a Python Dev. I'm currently being 24 and my favourite language is Python

2. str.format() - string interpolation

# a.) Interpolation with empty curly braces

print("My name is {} and I'm a {} and I'm {} \
years old and My favourite lan is {}".format(name, profession, age, language))

My name is Frank and I'm a Python Dev and I'm 24 years old and My favourite lan is Python

 # b.) Interpolation with tuple indexing
print("My name is {3} and I'm a {0} and I'm {1} \
years old and My favourite lan is {2}".format(profession, age, language, name))

My name is Frank and I'm a Python Dev and I'm 24 years old and My favourite lan is Python

# c.) Interpolation with dictionary key-value mapping
print("My name is {name} and I'm a {profession} and I'm {age} \
years old and My favourite lan is {language}".format(**person))

My name is Frank and I'm a Python Dev and I'm 24 years old and My favourite lan is Python

3. Python f-string Formatting

print(f"My name is {name} and I'm a {profession} and I'm {age} and I love {language}")

My name is Frank and I'm a Python Dev and I'm 24 and I love Python

Any inner curly braces as placeholders in a f-string are Python run-time !!!

native Python code can be executed!!!

# Convert the parameter to a String
def stringfy(value):

    return str(value)


## Run a function in a f-string placeholder

print(f"Hello, my age is stringfied here as {stringfy(value=24)}")

Hello, my age is stringfied here as 24

## Other operations: dictionary key indexing in f-string placeholders.
print(f"My name is {person['name']} and I'm a {person['profession']}")

My name is Frank and I'm a Python Dev