A formatted string is a variable which has been converted into a string (text). In python the specifics of how this is done is determined by what kind of variable you want to print.
Example 1: You have an experiment which generates a string variable called text. You want to insert this variable into a string so you can print it. This would be achieved with the following code:
message = 'The result is %s' %(text)
This will produce a variable message which if used in a text object would print the phrase ‘The result is’ followed by the variable text. In this instance %s is used as the variable being entered is a string. This is a marker which tells the script where the variable should be entered. %text tells the script which variable should be entered there.
Multiple formatted strings (of potentially different types) can be entered into one string object:
longMessage = 'Well done %s that took %0.3f seconds' %(info['name'], time)
Some of the handy formatted string types:
>>> x=5
>>> x1=5124
>>> z='someText'
>>> 'show %s' %(z)
'show someText'
>>> '%0.1f' %(x) #will show as a float to one decimal place
'5.0'
>>> '%3i' %(x) #an integer, at least 3 chars wide, padded with spaces
' 5'
>>> '%03i' %(x) #as above but pad with zeros (good for participant numbers)
'005'
See the python documentation for a more complete list.