CODEWITHSUNDEEP
listfilepython-3.x
mahmood
mahmood

Reputation: 24675

Comparing a list with file rows

I am trying to compare a list with the lines that are read from a text file. I asked a similar question here, but that does not work since the data are read from file and each line is splitted.

Assme a data file looks like

2 3 5
1 2 7 8 2
1 4 3 4 6

I read that file using

fs = open("in.txt")
lines = [line.split() for line in fs if line.strip()]

Then, I define a list like this

seen = []
seen.append(1)
seen.append(2)

Next, I compare the queue with each line to finda match using

take = [row for row in lines if row[:2] == seen]

However, take is empty although it should be 1 2 7 8 2. The complete code is

fs = open("in.txt")
lines = [line.split() for line in fs if line.strip()]
seen = []
seen.append(1)
seen.append(2)

take = [row for row in lines if row[:2] == seen]
if len(take) != 0:
    print(take)
else:
    print("no match")

As I debug the program I see that each line of the file is presented like ['1', '2', '7', '8', '2'] while the seen list looks like [1 2]. How can I fix that?

Upvotes: 0

Views: 164

Answers (1)

Oni1
Oni1

Reputation: 1505

When you are reading the input file in a list, the content of the list is strings.. You have only to type cast each entry...

fs = open("in.txt")
lines = [[int(strNumber) for strNumber in line.split()] for line in fs if line.strip()]

The rest should be similar.. Perhaps you should also handle exception if the content is not convertable to a integer..

Upvotes: 1

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