How to convert numbers to words using Python?

Converting numbers to words is a common requirement in applications like check writing, invoice generation, and text-based reports. Python's num2words library provides a simple way to convert numerical values to their word representations. For example, converting 1, 2, 29 to "one", "two", "twenty-nine" respectively.

Installing the num2words Library

Before using the library, install it using pip ?

pip install num2words

Basic Number to Words Conversion

The num2words() function converts integers and floats to their word equivalents ?

from num2words import num2words

# Convert simple integers
print(num2words(42))  

# Convert larger numbers
print(num2words(1234567))  

# Convert decimal numbers
print(num2words(13.5))  

forty-two
one million, two hundred and thirty-four thousand, five hundred and sixty-seven
thirteen point five

Advanced Conversion Options

The num2words() function accepts optional parameters for different conversion formats ?

• to: Specifies output format (cardinal, ordinal, year, currency)
• lang: Sets the language for conversion
• currency: Defines currency type when using currency format

from num2words import num2words

# Currency conversion (USD)
print(num2words(1234.56, to='currency', currency='USD'))

# Different language (French)
print(num2words(42, lang='fr')) 

# Ordinal numbers 
print(num2words(42, to='ordinal'))  

# Year format
print(num2words(2023, to='year'))

one thousand, two hundred and thirty-four dollars, fifty-six cents
quarante-deux
forty-second
twenty twenty-three

Practical Examples

Here are common use cases for number-to-word conversion ?

from num2words import num2words

# Check amount in words
check_amount = 2500.75
print(f"Amount: {num2words(check_amount, to='currency', currency='USD').title()}")

# Position/ranking
position = 3
print(f"Position: {num2words(position, to='ordinal').title()}")

# Multiple numbers conversion
numbers = [15, 100, 1000, 5000]
for num in numbers:
    print(f"{num} ? {num2words(num)}")

Amount: One Thousand, Two Hundred And Fifty Dollars, Seventy-Five Cents
Position: Third
15 ? fifteen
100 ? one hundred
1000 ? one thousand
5000 ? five thousand

Conclusion

The num2words library provides an efficient way to convert numbers to words in Python. It supports multiple formats including currency, ordinals, and different languages, making it versatile for various applications like financial documents and internationalized software.