如何遍历 python 中的连续行？

Question

I have a text file that, for the sake of simplicity, contains:

cat
dog
goat
giraffe
walrus
elephant

How can I create a script that would set a variable, animal in this case, to the first line in the text file, print animal, but then do the whole thing again, but make animal set to the next line (in this instance, dog).

Here's what I've tried so far:

while True:
    with open('./text.txt','r') as f:
        for i in enumerate('./text.txt'):
            if i in lines:
                print(lines)

Answer 1

Use readlines to store each line in a list.

with open('file.txt','r') as f:
    animals = f.readlines()

for animal in animals:
    print(animal.strip())

Answer 2

You could try the following:

with open('./text.txt') as f:
    for animal in f.readlines():
        print(animal.strip())

Answer 3

If you want to read the file one line at a time (which may be needed for large files):

with open('./text.txt','r') as f:
    line = True
    # this will stop when there is nothing left to read, as line will be ''
    # note that an 'empty' line will still have a line ending, i.e. '\n'
    while line:
        line = f.readline()
        print(line)

If you don't care about the size, you can read all lines at once with .readlines() and just loop over the returned values from that.