String formatting codes
Printing several variables in a single string is often easiest to do when you
use the Python string formatting codes. The following table lists all of the
formatting codes:
| s |
string conversion (or any object) |
X |
hexadecimal integer (uppercase letters) |
| c |
character |
e |
exponential notation (with lowercase 'e') |
| d |
signed decimal integer |
E |
exponential notation (with uppercase 'E') |
| i |
integer |
f |
floating point real number |
| u |
unsigned decimal integer |
g |
the shorter of %f and %e |
| o |
octal integer |
G |
the shorter of %f and %E |
| x |
hexadecimal integer (lowercase letters) |
% |
literal '%' |
You can modify the output further by adding to the basic codes.
| Symbol |
Function |
| - |
left justify |
| m.n |
m is the minimum total width and n is the number of
decimal digits to display (answer is rounded). |
| (var) |
maps a variable from a dictionary |
Sample code
>>> import math
>>> math.pi
3.1415926535897931
>>> print '%s' % math.pi
3.14159265359
>>> print '%f' % math.pi
3.141593
>>> print '%.2f' % math.pi
3.14
>>> print '%10.2f' % math.pi
3.14
>>> print '%e' % 300000000
3.000000e+008
>>> name = "Bob"
>>> age = 16
>>> print "My name is %s and I'm %s years old." % (name, age)
My name is Bob and I'm 16 years old.
>>> print "Name: %s Age: %s" % (name, age)
Name: Bob Age: 16
>>> print "Name: %10s Age: %s" % (name, age)
Name: Bob Age: 16
>>> print "Name: %-10s Age: %s" % (name, age)
Name: Bob Age: 16
>>> print "My name is %(name)s and I'm %(age)d years old." % \
{'name': 'Bob', 'age': 16}
My name is Bob and I'm 16 years old.
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