CODEWITHSUNDEEP
pythonlistpython-2.7max
nutship
nutship

Reputation: 4924

Finding a tuple with greatest value

Given these two lists:

first = [('-2.50', '1.91', '2.03'), ('3.00', '1.83', '2.08')]
second = [(('-2.50', 0.889258, 1.069258), ('3.00', 0.931381, 1.021381))]

It's a two-task challenge. Firslty, in list second, I need to identify a tuple with greatest value in it (while values at position 0 here: -2.50 and 3.00 must be ignored). Then, as a second task, we need to output the corresponding tuple form list first. So it should result in:

('-2.50', '1.91', '2.03')

This is because the greatest value found in step first should be 1.069258 which is inside 1st tuple.

The snag I face here is finding the tuple with greatest value (I know I can use max() to find the value but I need the whole tuple), with the 2nd part of the problem I think I'll cope simply using the if statement.

Upvotes: 0

Views: 131

Answers (3)

Ashwini Chaudhary
Ashwini Chaudhary

Reputation: 250931

One liner:

>>> first [ max(enumerate(second[0]), key=lambda x: max(x[1][1:] ))[0] ]
('-2.50', '1.91', '2.03')

or:

>>> maxx = float("-inf")
>>> for i,x in enumerate(second[0]):
...     temp = max(x[1:]) 
...     if temp > maxx:
...         index = i
...         maxx = temp
...         
>>> first[i]
('-2.50', '1.91', '2.03')

Upvotes: 1

yardsale8
yardsale8

Reputation: 945

You want to use a key function to compute the value by which each tuple is compared. You want to compare the tuples by the largest value other than the first, so try

>>> max(second[0], key = lambda x: max(x[1:]))
('-2.50', 0.889258, 1.069258)

Upvotes: 0

mgilson
mgilson

Reputation: 309899

In 1 line:

>>> max(zip(first,second[0]),key=lambda x:max(x[1][1:]))[0]
('-2.50', '1.91', '2.03')

Upvotes: 5

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