obtain parameters from a dictionary in python

Question

I am thinking about an elegant way of obtaining all the parameters I need. They are located in a text file. I usually read them into a dictionary (like "parameter1":10; "parameter2":20). But I usually do not need all the parameter, eg in some case I don't need to set "parameter1" in the text file. I have 2 ways of doing it: 1) always set all the parameters in the text. If I don't need any one, set it to 0. 2) check if the parameter is available in the dictionary like:

try p1 = dict1.get("parameter1"):
except:
    p1 = 0

Same process can be done if I need the parameter but forget to set. The code can set it to a default value. In case of 100 parameters, what I am doing is to repeat this "try, except 100 times" which is not so elegant. I wonder if there is any better choice? The method can be totally different which I don't care since it is just a small step of initializing parameters.

Thanks.

Answer 1

You can use the second parameter in get to specify a default value if the key is not found

d = {"parameter1":10, "parameter2":20}

>>> d.get('parameter1', 100)    # Key exists, will retrieve the value
10

>>> d.get('parameter3', 100)    # Key does not exist, retrieves default value
100