I have several values, like this:
value_a = 5
value_b = 10
value_c = 20
I want to find the largest value and print the NAME of the value. normally I would use
val = [value_a, value_b, value_c]
print max (val)
but this only gives me the value and not the name.
Instead of defining variable, you need to create a dict to map the name with the value. Then you need to call max() with operator.itemgetter() as key to it. For example:
my_dict = {
'value_1': 10,
'value_2': 30,
'value_3': 20
}
from operator import itemgetter
var_text, value = max(my_dict.items(), key=itemgetter(1))
# Value of:
# `var_text`: "value_2"
# `value`: 30
Here, max() will return the tuple with maximum value in the dict.
If you do not care about the maximum value, and you just want the key holding it, you may do:
>>> max(my_dict, key=my_dict.get)
'value_2'
Explanation:
my_dict.items() will return list of tuple in the format [(key, value), ..]. In the example I gave, it will hold:
[('value_1', 10), ('value_3', 20), ('value_2', 30)]
key=itemgetter(1) in the satement will tell max() to perform the max operation on the index 1 of each tuple in the list.
How about this. :)
In [1]: the_dict = {'value_a':5, 'value_b':10, 'value_c':20}
In [2]: max(the_dict, key=the_dict.get)
The output:
Out[2]: 'value_c'
You need to use dictionary or named tuple. Example using dictionary is below
Python 3.4.3 (default, Sep 14 2016, 12:36:27)
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> vdict={'value_a':5,'value_b':10,'value_c':20}
>>> max(vdict, key=vdict.get)
'value_c'
>>>
Make a dictionary for the values and then simply call this function in the print statement.
values = {
'value_1': 10,
'value_2': 30,
'value_3': 20
}
print (max(values, key=lambda i: values[i]))
Output:
value_2
