Note: All examples below were executed in Python interactive shell (REPL - Read, Eval, Print and Loop).

Format specification:⌗

[[fill]align][sign][#][0][width][grouping_option][.precision][type]

- [width]

>>> f'{"text":10}'
'text      '

- [[fill]align]

>>> f'{"test":#>10}'
'######test'
>>> f'{"test":#<10}'
'test######'
>>> f'{"test":#^10}'
'###test###'

- [[fill]align] with numbers

>>> f'{12345:0>10}'
'0000012345'

negative numbers

>>> f'{-12345:0=10}'
'-000012345'

- [0] shortcut (no align)

>>> f'{12345:010}'
'0000012345'
>>> f'{-12345:010}'
'-000012345'

- [.precision]

>>> import math
>>> math.pi
3.141592653589793
>>> f'{math.pi:.2f}'
'3.14'

- [grouping_option]

>>> f'{1000000:,.2f}'
'1,000,000.00'
>>> f'{1000000:_.2f}'
'1_000_000.00'

- [sign] (+/-)

>>> f'{12345:+}'
'+12345'
>>> f'{-12345:+}'
'-12345'
>>> f'{-12345:+10}'
'    -12345'
>>> f'{-12345:+010}'
'-000012345'

- [type]

binary

>>> f'{10:b}'
'1010'

octal

>>> f'{10:o}'
'12'

hexadecimal

>>> f'{200:x}'
'c8'
>>> f'{200:X}'
'C8'

scientific notation

>>> f'{345600000000:e}'
'3.456000e+11'

character type

>>> f'{65:c}'
'A'

- [type] with notation (base)

>>> f'{10:#b}'
'0b1010'
>>> f'{10:#o}'
'0o12'
>>> f'{10:#x}'
'0xa'

- percentage (multiply by 100)

>>> f'{0.25:0%}'
'25.000000%'
>>> f'{0.25:.0%}'
'25%'