syntax difference

[Ben Finney]

Sharan Basappa <sharan.basappa at gmail.com> writes:

> I think I am now confused with format options in Python.

You should refer to the documentation for string formatting
<URL:https://docs.python.org/3/library/stdtypes.html#str.format>
<URL:https://docs.python.org/3/library/string.html#formatstrings>

(or, if you want to continue with the older less-flexible style,
<URL:file:///usr/share/doc/python3/html/library/stdtypes.html#printf-style-string-formatting>)

> I tried an example as below and both print proper value:
>
> age = 35
>
> print "age is %s" % age

The ‘s’ format specifier says “Ask the object for its text
representation, and put that text here”.

Every object has a text representation, so ‘s’ works with any object.

> print "age is %d" % age

The ‘d’ format specifier says “Format the integer as a decimal text
representation, and put that text here”.

Only objects that are integers (or that implement the format-as-decimal
API) will work with ‘d’.

> I other languages I know the format specifier should be same as the
> variable type. For example, in the above case, it has to be %d and not
> %s

Because you are explicitly specifying which formatting to use, there's
no ambiguity. With an object that is an integer, either of the above
makes sense in different use cases.

-- 
 \        “A right is not what someone gives you; it's what no one can |
  `\                                     take from you.” —Ramsey Clark |
_o__)                                                                  |
Ben Finney