CODEWITHSUNDEEP
python-3.x
Jake Myers
Jake Myers

Reputation: 13

I'm using a 2d list, not really sure how to find a minimum value on a, or multiple specific row(s)

So I'm trying to run a matrix through Dijkstra's algorithm. I have a 2d list comprised of values or inf, I want to scan through the first list and find the smallest value. in the case below 5.

lst = [['inf', '10', 'inf', '5', 'inf'],
       ['inf', 'inf', '1', '2', 'inf'], 
       ['inf', 'inf', 'inf', 'inf', '4'], 
       ['inf', '3', '9', 'inf', '2'], 
       ['7', 'inf', '4', 'inf', 'inf']]

I know I need to use some version of lst[0:] to specify that list but not really sure exactly how to implement it.

Upvotes: 0

Views: 33

Answers (2)

Patrick Haugh
Patrick Haugh

Reputation: 60954

Note that your list of lists contains strings. You likely want to treat the values as floats

lst = [['inf', '10', 'inf', '5', 'inf'],
       ['inf', 'inf', '1', '2', 'inf'], 
       ['inf', 'inf', 'inf', 'inf', '4'], 
       ['inf', '3', '9', 'inf', '2'], 
       ['7', 'inf', '4', 'inf', 'inf']]

print(min(float(x) for x in lst[0]))
# 5.0 min of first list
print(min(float(x) for y in lst for x in y))
# 1.0 min of all lists

The naive lexicographic minimum of lst[0] is '10'

Upvotes: 0

John Zwinck
John Zwinck

Reputation: 249123

lst[0] is the first element of lst which is the first sublist.

min(lst[0]) is the smallest value in the first sublist.

Upvotes: 2

Related Questions