For reference: Python 3 documentation for the newer format() formatting style and the older % -based formatting style.

Use 'classic' string substitutions (ala C's printf). Note the different meanings here of % as the string-format specifier, and the % to apply the list (actually a tuple) to the formatting string.

How do I print an integer with commas as thousands separators? 1234567 1,234,567 It does not need to be locale-specific to decide between periods and commas.

How do I pad a numeric string with zeroes to the left, so that the string has a specific length?

May 21, 2012 · Note that the % method is not depreciated in Python 3.6. It will continue to be supported in lieu of its similarity to c, c++, etc. str.format() and f-strings are preferred but not enforced.

Both make it easier to not get confused about where print() starts and ends and where the formatting takes place. In both f-strings and str.format(), use !r after the field to get the repr() output, just like %r …

The format specifier inside the curly braces follows the Python format string syntax. Specifically, in this case, it consists of the following parts: The empty string before the colon means "take the next …

111 I'm using the .format() a lot in my Python 3.5 projects, but I'm afraid that it will be deprecated during the next Python versions because of f-strings, the new kind of string literal.

f-strings (python 3) You can avoid having to double the curly brackets by using f-strings ONLY for the parts of the string where you want the f-magic to apply, and use regular (dumb) strings for everything …

Aug 3, 2010 · This method of string formatting is the new standard in Python 3.0, and should be preferred to the % formatting described in String Formatting Operations in new code.