Find maximum value in a list of dicts-CodePudding

I'm new to Python, and I've been stuck at one point for several days now.

There is a list of dicts like this one:

dd = [{'prod': 'White', 'price': '80.496'}, {'prod': 'Blue', 'price': '9.718'}, {'prod': 'Green', 'price': '7161.3'}]

I need to output the value in prod based on the maximum value of the price.

Here is the desired result: Green

I have tried many ways based on information I found on SO:

dd = [{'prod': 'White', 'price': '80.496'}, {'prod': 'Blue', 'price': '9.718'}, {'prod': 'Green', 'price': '7161.3'}]
L = [v for v in dd if v['price']==max([u['price']for u in dd])][0]['prod']
print(L)

Output: Blue

(Almost correct, but "Blue" does not have the maximum value of the price!)

dd = [{'prod': 'White', 'price': '80.496'}, {'prod': 'Blue', 'price': '9.718'}, {'prod': 'Green', 'price': '7161.3'}]
L = max(dd, key=lambda x:x['price'])
print(L)

Output: {'prod': 'Blue', 'price': '9.718'}

dd = [{'prod': 'White', 'price': '80.496'}, {'prod': 'Blue', 'price': '9.718'}, {'prod': 'Green', 'price': '7161.3'}]
L = max(e['price'] for e in dd)
print(L)

Output: 9.718

from operator import itemgetter
dd = [{'prod': 'White', 'price': '80.496'}, {'prod': 'Blue', 'price': '9.718'}, {'prod': 'Green', 'price': '7161.3'}]
L = max(map(itemgetter('price'), dd))
print(L)

Output: 9.718

dd = [{'prod': 'White', 'price': '80.496'}, {'prod': 'Blue', 'price': '9.718'}, {'prod': 'Green', 'price': '7161.3'}]
seq = [x['price'] for x in dd]
L = max(seq)
print(L)

Output: 9.718

In all cases, the maximum value is 9.718 and not 7161.3. How can I fix this? I'm using MS Visual Studio running Python 3.9.

CodePudding user response：

You need to convert the price values to floats for the key parameter:

max(dd, key=lambda x: float(x['price']))['prod']

This outputs:

Green