Question

what does the % mean in lines of code such as this

http://dpaste.com/607203/

Answer 1

The item in demolist replaces the % sign. The % tells the function to insert whatever was given to it, in this case each item in demolist.

Answer 2

In Python, the % symbol is used in print to introduce a format specifier (more commonly known as a conversion specifier) and also as a formatting or interpolation operator .

http://en.wikipedia.org/wiki/Printf#1990s:_PHP.2C_Python

It's used in the printf class of functions in several different programming languages. In Python it's used like this:

print "%s and %s." % ('Spam', 'Eggs')

which outputs:

>> Spam and Eggs.

you supply print with a format string containing conversion specifiers like %s inside it (there are many other conversion specifiers like %d and %f and %x etc. %s is a conversion specifier that converts an object into a string and inserts it into the format string when it is rendered and printed into the output stream).

print '%s and %s.'

In Python, you must use the % operator between the format string and a tuple containing the objects you want to render inside the format string.

I want to print out Spam and Eggs so I use the tuple ('Spam', 'Eggs') containing two strings, 'Spam', and 'Eggs'.

print '%s and %s.' % ('Spam', 'Eggs')

http://docs.python.org/library/stdtypes.html

contains a list of conversion specifiers you may use with print. You can combine many options with conversion specifiers. For example:

hours = 3
minutes = 15
seconds = 0
print "%.2d:%.2d:%.2d" % (hours, minutes, seconds)

outputs:

>> 03:15:00

I included .2 in the %d conversion specifier to make the program print at least 2 digits per decimal number.

Answer 3

http://docs.python.org/library/stdtypes.html#string-formatting-operations