Formatting strings in Python is very common. Older styles use a combination of % and .format() to format strings. Newer styles use what are called f-strings.
Formatting strings using f-strings are very flexible. One thing that wasn't clear is how to specify the width of strings.
To create an f-string, you must be using Python 3 and type out something like this.
greet = 'Hello'
print(f"{greet}, World!")
# Hello, World
I ran into a situation where I wanted to format an aligned text. To do so, you can use the syntax used in other Python formatting.
init = 34
end = 253
print(f"You had this much money : ${init:5}")
print(f"Now you have this much money : ${end:5}")
# You had this much money : $ 34
# Now you have this much money : $ 253
# Spacing width 12345
Note the annotation of spacing width with the numbers 1 through 5 to show the spacing differences.
The basic syntax is
{variable:width.precision}
With this syntax, you can even pass variables for each of those values for more dynamic control.
width = 10
precision = 4
value = decimal.Decimal("12.34567")
f"result: {value:{width}.{precision}}"
# result: 12.35
One last fun thing you have control over is you can align these values using the less than and greater than symbols for right-aligned (>) or left-aligned (<).
place = 'here'
print(f"You can have the word {place:<10}")
print(f"Or you have the word {place:>10}")
# You can have the word here
# Or you have the word here
More reference material on how to format strings can be found here.
Top comments (1)
Thanks! Very helpful. Though I wondered where you found this documented. AFAICT, the link you provided (docs.python.org/3/library/string.html#format-string-syntax) doesn't cover f-strings but only the old-school strings. After searching a little… You might consider adding links to (a) 2.4.3. Formatted string literals (docs.python.org/3/reference/lexical_analysis.html#f-strings) and/or (b) PEP 498 – Literal String Interpolation