CODEWITHSUNDEEP
pythondjango
yanchenko
yanchenko

Reputation: 57216

'%s' % 'somestring'

Here are a couple of examples taken from django-basic-apps:

# self.title is a unicode string already
def __unicode__(self):
        return u'%s' % self.title

# 'q' is a string
search_term = '%s' % request.GET['q']

What's the point of this string formatting?

Upvotes: 5

Views: 307

Answers (5)

Nathan Borror
Nathan Borror

Reputation: 46

It's just a habit of mine. In these cases it's not necessary.

Upvotes: 3

Eric O. Lebigot
Eric O. Lebigot

Reputation: 94605

Another idea: Maybe this is done with possible future implementations in mind? self.title and request.GET[…] are currently already of the desired type, but implementation details might change in the future, and they might stop being a unicode string or a string.

Now, I would have used str() and unicode(), though…

Upvotes: 0

Antony Hatchkins
Antony Hatchkins

Reputation: 34044

Maybe the author is used to strictly typed languages and he misses it in python and this is his way to make python more strictly typed than it is.

Here - to make the types of input/output parameters clear only for the reader because provided all is working as expected it is just useless for the python itself.

Upvotes: 0

Wogan
Wogan

Reputation: 72747

You're probably better off asking Nathan Borror, the author. It may just be a personal style.

Django does use proxy objects for strings in some cases though, so it may be to force them to "actual" strings. I believe these proxies are for i18n/l10n purposes (don't quote me on that, could also be to avoid db lookups until needed, or a number of other reasons).

Upvotes: 1

user25148
user25148

Reputation:

At first glance, it doesn't look sensible, but it does have the benefit of forcing the result to be a string (or unicode string), rather than whatever it might have been from before. Another way to do the same thing might be to call str on the format argument (or unicode).

Upvotes: 1

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