CODEWITHSUNDEEP
pythonfiledictionary
Wind Craft
Wind Craft

Reputation: 15

Python import data from file to dictionary and compare data

I tried to import some keys and value from a relatively small file into a dictionary using this code

winner = {}
with open ("Scores.txt") as file:
    for line in file:
        (key, val) = line.split()
        winner[key] = val

my file contains something like this:

Jeff 66
Tom 72
Aaron 34
Eva 47
Aaron 33
Jeff 36
Tom 34
Aaron 67
Tom 76

When I print out the dictionary, the value got overwritten by the data with the same key. I want to keep the highest score for each player without changing the file.

Here is the pseudocode of the things I would like to do:

If the value in file > value in key:
    replace the value in key with the value in file
Else:
    Do nothing

Upvotes: 1

Views: 91

Answers (2)

Lomtrur
Lomtrur

Reputation: 1798

You could collect all values for each key and then take the max. Or instead, read each line, get the key and value and check if the value is higher than the current value. If it is, replace it. The default value for defaultdict(int) is 0, so that should always be lower than any score you have in your file.

from collections import defaultdict

winner = defaultdict(int)
with open ("Scores.txt") as file:
    for line in file:
        (key, val) = line.split()
        val = int(val)
        if val > winner[key]:
            winner[key] = val
print(winner)

Prints defaultdict(<class 'int'>, {'Jeff': 66, 'Tom': 76, 'Aaron': 67, 'Eva': 47})

If there can be negative scores, use defaultdict(lambda: -10000) (or any other negative number, lower than the lowest possible score).

Upvotes: 1

Chris
Chris

Reputation: 29742

Use dict.get and max:

winner = {}
with open ("Scores.txt") as file:
    for line in file:
        (key, value) = line.split()
        winner[key] = max(winner.get(key, 0), int(value))
print(winner)
{'Aaron': 67, 'Eva': 47, 'Jeff': 66, 'Tom': 76}

Explanation:

  • winner.get(key, 0): returns value if winner already has the key, else 0
  • max(winner.get(key, 0), int(value)): compares max for each entry of your dict

Upvotes: 1

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