Menu
Is it possible to use a variable inside of a Python string formatting specifier?
I have tried:
display_width = 50 print('\n{:^display_width}'.format('some text here')) but get a ValueError: Invalid format specifier. I have also tried display_width = str(50)
however, just entering print('\n{:^50}'.format('some text here')) works just fine.
737
If you can depend on having Python >= version 3.6, then you have another attractive option, which is to use the new formatted string literal (f-string) syntax to insert variable values. An f at the beginning of the string tells Python to allow any currently valid variable names as variable names within the string.
The format() method formats the specified value(s) and insert them inside the string's placeholder. The placeholder is defined using curly brackets: {}. Read more about the placeholders in the Placeholder section below. The format() method returns the formatted string.
format() is that you can swap out the template, the advantage of f-strings is that makes for very readable and compact string formatting inline in the string value syntax itself.
Yes, but you have to pass them in as arguments to format, and then refer to them wrapped in {} like you would the argument name itself:
print('\n{:^{display_width}}'.format('some text here', display_width=display_width)) Or shorter but a little less explicit:
print('\n{:^{}}'.format('some text here', display_width)) Since this question was originally posted, Python 3.6 has added f-strings, which allow you to do this without using the format method and it uses variables which are in scope rather than having to pass in the named variables as keyword arguments:
display_width = 50 text = 'some text here' print(f'\n{text:^{display_width}}') If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
