Formatting Strings in Python: The Easy Way

Python allows you to insert text and variables into strings to create informative messages. There are two main ways to do this:

1. Old Style Formatting (Less Flexible)

   • Uses a percent sign % and numbers to specify placeholders for your data.

   • Not easy to read or understand for somplex formatting.

2. New Style Formatting (More Flexible and Recommended)

   • Uses curly braces {} and names to define placeholders.

   • Offers more control over how your data is displayed (alignment, padding etc.).

Let's see some examples!

Basic Formatting:

name = "John"

# Old style (confusing)
greeting = "Hello, %s" % name # %s is the placeholder

# New style (better)
greeting = "Hello, {}".format(name) # {} is the plaaceholder 
print(greeting) # Output: Hello, Alice

Making Things Clearer:

New style formatting allows you to give cleare names to your placeholders, making your code easier to understand, especially when dealing with multiple pieces of data.

person = {"name": "John", "age": 21}

# Old style (confusing)
message = "My name is %s and I am %d years old." % (person["name"], person["age"])

# New style (better)
message = "My name is {name} and I am {age} years old.".format(**person)  # **person unpacks the dictionary 
print(message)  # Output: My name is John and I am 21 years old.

Advanced Formatting Options

Padding with zeros:

money_formatted = "{:>10.2f}".format(123.4567)  # Right align, 10 spaces, 2 decimal places 
print(money_formatted)  # Output:     123.46

Shortening long text:

long_text = "This is an extremely long sentence that goes on and on..."
shortened_text = "{:.10}".format(long_text)  # Shorten to 10 characters 
print(shortened_text)  # Output: This is an...

Formatting Dates:

from datetime import datetime

now = datetime.now()

# Date only (YYYY-MM-DD)
formatted_date = "{:%Y-%m-%d}".format(now)
print(formatted_date)  # Example output: 2024-03-11

# Date and time (YYYY-MM-DD HH:MM:SS)
formatted_datetime = "{:%Y-%m-%d %H:%M:%S}".format(now)
print(formatted_datetime)  # Example output: 2024-03-11 19:23:11

Key tips:

• Use new style formatting .format() for better readability and flexibility.

• Give clear names to your placeholders to make your code easier to understand.

• Play around with formatting options to achieve the results you want.

Thank you for reading 😁