Convert Unicode data to int in python

Question

I am getting values passed from url as :

user_data = {} if (request.args.get('title')) :     user_data['title'] =request.args.get('title') if(request.args.get('limit')) :     user_data['limit'] =    request.args.get('limit') 

Then using it as

if 'limit' in user_data :     limit = user_data['limit'] conditions['id'] = {'id':1} int(limit) print type(limit) data = db.entry.find(conditions).limit(limit) 

It prints : <type 'unicode'>

but i keep getting the type of limit as unicode, which raises an error from query!! I am converting unicode to int but why is it not converting?? Please help!!!

Answer 1

int(limit) returns the value converted into an integer, and doesn't change it in place as you call the function (which is what you are expecting it to).

Do this instead:

limit = int(limit) 

Or when definiting limit:

if 'limit' in user_data :     limit = int(user_data['limit']) 

Answer 2

In python, integers and strings are immutable and are passed by value. You cannot pass a string, or integer, to a function and expect the argument to be modified.

So to convert string limit="100" to a number, you need to do

limit = int(limit) # will return new object (integer) and assign to "limit" 

If you really want to go around it, you can use a list. Lists are mutable in python; when you pass a list, you pass it's reference, not copy. So you could do:

def int_in_place(mutable):     mutable[0] = int(mutable[0])  mutable = ["1000"] int_in_place(mutable) # now mutable is a list with a single integer 

But you should not need it really. (maybe sometimes when you work with recursions and need to pass some mutable state).