62 – Formatting big numbers

62 – Formatting big numbers#

When doing string formatting with big integers, you may want to include thousands separators to make numbers easier to read. You can add

commas;
underscores; or
a locale-appropriate separator.

To do so, use the specifiers ,, _, or n, respectively:

bignum = 123541241234

print(f"Big money ${bignum:,}")
# Big money $123,541,241,234

print(f"Big money ${bignum:_}")
# Big money $123_541_241_234

print(f"Big money ${bignum:n}")
# Big money $123541241234  # Might be different for you.

Note that the locale-appropriate separator might be “nothing” if the locale isn’t set appropriately beforehand, as seen above.

Since Python 3.14, you can also group digits in the fractional part of a number.