x = " \{ Hello \} {0} "
print(x.format(42))
gives me : Key Error: Hello\\
I want to print the output: {Hello} 42
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}}
.