See fstring.help for more examples and for a more detailed discussion of this syntax see this string formatting article.
The below examples assume the following variables:
>>> number = 4125.6
>>> percent = 0.3738
| Example Output | Replacement Field | Fill | Width | Grouping | Precision | Type |
|---|---|---|---|---|---|---|
'4125.60' |
{number:.2f} |
.2 |
f |
|||
'4,125.60' |
{number:,.2f} |
, |
.2 |
f |
||
'04125.60' |
{number:08.2f} |
0 |
8 |
.2 |
f |
|
' 4125.60' |
{number: 8.2f} |
|
8 |
.2 |
f |
|
'4.1e+03' |
{number:.2g} |
.2 |
g |
|||
'4125.6' |
{number:.8g} |
.8 |
g |
|||
'37%' |
{percent:.0%} |
.0 |
% |
These format specifications only work on all numbers (both int and float).
f with precision .n displays n digits after the decimal point.g with precision .n displays n significant digits in scientific notation. Trailing zeros are not displayed.These examples assume the following variable:
>>> number = 10
| Example Output | Replacement Field | Alt | Fill | Width | Grouping | Type |
|---|---|---|---|---|---|---|
'0010' |
{number:04d} |
0 |
4 |
d |
||
' 10' |
{number: 4d} |
|
4 |
d |
||
'10' |
{number:,} |
, |
||||
'1010' |
{number:b} |
b |
||||
'a' |
{number:x} |
x |
||||
'A' |
{number:X} |
X |
||||
'0xa' |
{number:#x} |
# |
x |
|||
'000a' |
{number:04x} |
0 |
4 |
x |
||
'0000_1010' |
{number:09_b} |
0 |
9 |
_ |
b |
An empty type is synonymous with d for integers.
These format specifications only work on integers (int).
These examples assume the following variable:
>>> string = "Python"
| Example Output | Replacement Field | Fill Char | Align | Width |
|---|---|---|---|---|
' Python' |
{string:>20} |
> |
20 |
|
'Python ' |
{string:<20} |
< |
20 |
|
' Python ' |
{string:^20} |
^ |
20 |
|
'0000Python' |
{string:0>10} |
0 |
> |
10 |
These format specifications work on strings (str) and most other types (any type that doesn't specify its own custom format specifications).
The below modifiers are special syntaxes supported by all object types.
Some format specifications are also included to show how to mix and match these syntaxes with the : syntax.
| Self-Doc | Conversion | Format Spec | Field | Example Output |
|---|---|---|---|---|
!s |
{expression!s} |
'Hi! ✨' |
||
!r |
{expression!r} |
"'Hi! ✨'" |
||
!a |
{expression!a} |
"'Hi! \\u2728'" |
||
!r |
<10 |
{expression!r:<10} |
"'Hi! ✨' " |
|
= |
{expression=} |
"name='Trey'" |
||
= |
{expression = } |
"name = 'Trey'" |
||
= |
!s |
{expression=!s} |
"name=Trey" |
|
= |
.2f |
{expression=:.2f} |
'len(name)=4.00' |
An empty conversion field is synonymous with !s, unless a self-documenting expression is used.
When a self-documenting expression is used, an empty conversion field uses !r.
See fstring.help for some examples.