How do I loop through **kwargs in Python?

Question

In the code below, I want to read obj.subject and place it into var subject, also read obj.body and place it into body. First I want to read the kwargs variables and search for keywords within the string to replace, if none exists then move on.

How can I iterate through kwargs in Python?

for key in kwargs:
    subject = str(obj.subject).replace('[%s]' % upper(key), kwargs[key])

for key in kwargs:
    body = str(obj.body).replace('[%s]' % upper(key), kwargs[key])

return (subject, body, obj.is_html)

Answer 1

For Python 3 users:

You can iterate through kwargs with .items()

subject = obj.subject
body = obj.body
for key, value in kwargs.items():
    subject = subject.replace('[%s]' % key.toupper(), value)
    body = body.replace('[%s]' % key.toupper(), value)

return (subject, body, obj.is_html)

For Python 2 users:

You can iterate through kwargs with .iteritems():

subject = obj.subject
body = obj.body
for key, value in kwargs.iteritems():
    subject = subject.replace('[%s]' % key.toupper(), value)
    body = body.replace('[%s]' % key.toupper(), value)

return (subject, body, obj.is_html)

Answer 2

Just a quick note for those upgrading to Python 3.

In Python 3 it's almost the same:

subject = obj.subject
body = obj.body
for key, value in kwargs.items():
    subject = subject.replace('[{0}]'.format(key.toupper()), value)
    body = body.replace('[{0}]'.format(key.toupper()), value)

return (subject, body, obj.is_html)

Notice that iteritems() becomes items() as dict no longer has the method iteritems.

Answer 3

you can iter on the dictionary as it provides by default iteration on its key.

subject = obj.subject
body = obj.body
    
for key in kwargs:
    subject = str(subject).replace([%s] % upper(key), kwargs[key])
    body = str(body).replace([%s] % upper(key), kwargs[key])

print(subject, body)

I tested it on Python 3 and Python 2 Interpreters and it is working totally fine for me so it will also work fine for you. There is a default for all the structures whether its List or Dictionary or tuple you can Iter on it easily in the python language.

Attaching a photo depicting that we can do that so easily.