Wayne Werner wrote:
In this case it's not actually modulus, it's just the syntax for string
formatting. I'm not sure *what* the reasoning behind the % was, but that's
the way it is.
I believe the designers of the C programming language are to blame.
[...]
In old style formatting, you use a string with format specifiers (%s, %d,
etc.) followed by a tuple of arguments. Here, the lengths have to match
exactly - if you have one specifier then you must have a 1-element tuple.
That's actually wrong. If you have one specifier, you must have one
object of any sort *except* a tuple.
>>> "%s" % 42 # One object not a tuple.
'42'
But if you have a tuple, the % formatting will try to use each element
in the tuple separately:
>>> "%s" % (23, 42) # One object which is a tuple
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: not all arguments converted during string formatting
So if you actually want to use a tuple as the object, you need to wrap
it in a single item tuple:
>>> "%s" % ((23, 42),) # Tuple inside a tuple.
'(23, 42)'
--
Steven
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