CODEWITHSUNDEEP
pythonlisttuples
TheFoxx
TheFoxx

Reputation: 1693

How to find the max number in this type of data structure in Python

Im not entirely sure what the name of this type of data structure (a table??),

T = [[(0, ''), (-1, '<'), (-2, '<')], [(-1, '^'), (1, '\\'), (0, '\\')], [(-2, '^'), (5, '^'), (0, '\\')]]

Anyway, we're using it in college for a certain type of program, but that doesn't really matter, basically I have a very complex program already done which use's this type of data structure, however now I need to write another program that does something very similar, basically it would save me a great deal of work if there was a way to get the maximum number from this list of tuples, in a list of lists, along with the index of that value. Also the number of tuples, or lists is not fixed, that will change depending on the length of a string put into the program. It also important to note I am not just looking for the maximum number, but also the index of that number. With this type of data structure,

T[2][2][1]

would return

'\ \'

In the example I gave above I would be looking for 

T[2][1][0]

which would return

5

Any help is greatly appreciated :)

Upvotes: 1

Views: 152

Answers (4)

Lev Levitsky
Lev Levitsky

Reputation: 65851

Good old way?

def find_max(table):
    max_val = table[0][0][0] # something to start with
    max_index = (0, 0)
    for l in table:
        for t in l:
            if t[0] > max_val:
                max_val = t[0]
                max_index = (table.index(l), l.index(t))
    return (max_val, max_index)

Upvotes: 0

hochl
hochl

Reputation: 12960

T=[[(0, ''), (-1, '<'), (-2, '<')], [(-1, '^'), (1, '\\'), (0, '\\')], [(-2, '^'), (5, '^'), (0, '\\')]]

m, ma, mb=None, 0, 0
for a in xrange(len(T)):
        for b in xrange(len(T[a])):
                if m is None or T[a][b] > m:
                        m, ma, mb=T[a][b], a, b

print m, ma, mb

This will print

(5, '^') 2 1

Upvotes: -1

Andrew Clark
Andrew Clark

Reputation: 208665

Here is a pretty concise method:

max((k, (i, j)) for i, lst in enumerate(T) for j, (k, _) in enumerate(lst))

For your sample data:

>>> T = [[(0, ''), (-1, '<'), (-2, '<')], [(-1, '^'), (1, '\\'), (0, '\\')], [(-2, '^'), (5, '^'), (0, '\\')]]
>>> max((k, (i, j)) for i, lst in enumerate(T) for j, (k, _) in enumerate(lst))
(5, (2, 1))
>>> T[2][1]
(5, '^')

Upvotes: 2

Ethan Furman
Ethan Furman

Reputation: 69248

Homework, eh? Here's some clues:

  • iterate through the list, and the list, and compare the 0th values

  • enumerate is you friend

Not homework? OKay, here's a solution :)

high = 0
index = None
for i, lst in enumerate(T):
    for j, tpl in enumerate(lst):
        current = T[i][j][0]
        if current > high:
            index = i, j, 0
        high = max(high, current)

print index

Upvotes: 0

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