Formatted Printing in Python

Python has no "printf" or "sprintf" - use the % operator on a string object which is the format string instead. Let me show you that ...

Firstly, what do we get if we do NOT format?

>>> val = 1. / 17.

>>> print val

0.0588235294118

Here it is, formatted to 4 figures after the decimal place:

>>> val24dp = "%.4f" % val

>>> print val24dp

0.0588

And with a total field width of 8 characters, of which 4 are after the decimal place (the 8 is a total width and NOT the number of places before!)

>>> f2 = "A seventeenth is %8.4f to 4 places" % val

>>> print f2

A seventeenth is   0.0588 to 4 places

Whole numbers are formatted with a "d" - that stands for "decimal" as opposed to "x" for hexadecimal, or the letter "o" for Octal.

>>> n = 5

>>> vv = "There are %3d in stock" % n

>>> print vv

There are   5 in stock

And if I want to format several values at the same time, I can do so by using multiple % based place holders, and then specifying a tuple for formatting.

>>> vx = "There are %d in stock at %.4fp each" % (n,val)

>>> print vx

There are 5 in stock at 0.0588p each

(written 2010-05-25)

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Course Lunches
The Perl Survey
Tell the Melksham Chamber or you only have yourself to blame
The 500 pound question to get you started
Formatted Printing in Python
The history and future of Melksham Chamber of Commerce
Learning to program in Python 2 ... and / or in Python 3
Blowing our own trumpet
Regional Spatial Strategy and the next 20 years - Whence Wiltshire under the new government?
Declarations of interest - knowing where you stand with people