How can I print literal curly-brace characters in a string and also use .format on it?
You need to double the {{ and }}:
>>> x = " {{ Hello }} {0} ">>> print(x.format(42))' { Hello } 42 'Here's the relevant part of the Python documentation for format string syntax:
Format strings contain “replacement fields” surrounded by curly braces
{}. Anything that is not contained in braces is considered literal text, which is copied unchanged to the output. If you need to include a brace character in the literal text, it can be escaped by doubling:{{and}}.
Python 3.6+ (2017)
In the recent versions of Python one would use f-strings (see also PEP498).
With f-strings one should use double {{ or }}
n = 42 print(f" {{Hello}} {n} ")produces the desired
{Hello} 42If you need to resolve an expression in the brackets instead of using literal text you'll need three sets of brackets:
hello = "HELLO"print(f"{{{hello.lower()}}}")produces
{hello}
You escape it by doubling the braces.
Eg:
x = "{{ Hello }} {0}"print(x.format(42))