Printing a percent sign

[John Machin]

Lawrence D'Oliveiro wrote:
> In message <1159230293.270822.50390 at d34g2000cwd.googlegroups.com>, John
> Machin wrote:
>
> > 1. Reasoning: How do you get a literal "'" into an SQL string constant?
> > How do you get a literal "\" into a Python string constant? How do you
> > get a literal "$" into some *x shell command lines? Do you detect a
> > pattern?
>
> None of which applies to escaping of % characters in format strings.

What I had in mind was:

where surname = 'O''REILLY'
install_dir = "C:\\Python25"
...
print "The interest rate is %.2f%% p.a." % (rate * 100.0)

the common pattern being that the problem character is doubled.