如何在python中一次从文件中读取四行

Question

我想一次读4或6行。我希望你们能帮我解决这个问题。

with open('readme.txt') as f:
list_of_4tuples = [ (line,f.readline()) for line in f ]
for (line1,line2,line3,line4) in list_of_4tuples: # Work with them in pairs.
print(f'a: {line1}{line2}{line3}{line4}')

Answer 1

(1、2、3、4),那么(2、3、4、5)

with open('readme.txt') as f:
lines = f.read().splitlines()
for (line1, line2, line3, line4) in zip(lines, lines[1:], lines[2:], lines[3:]): # Work with them in pairs.

print(f'a: {line1}{line2}{line3}{line4}')

如果你没有，行是重复的。

(1,2,3,4) then (5,6,7,8)

with open('readme.txt') as f:
for (line1, line2, line3, line4) in zip(f, f, f, f):

print(f'a: {line1}{line2}{line3}{line4}')

Answer 2

您可以创建四个迭代器，它们以不同的偏移量同时遍历行。

with open('readme.txt') as f:
lines = f.readlines()
iterators = [iter(lines) for _ in range(4)]
for k in range(1, 4):
for j in range(4-k, 4):
next(iterators[j]) # advance the iterators
for line1, line2, line3, line4 in zip(*iterators):
...