我如何从 python 中的 filei 读取前 10 行和最后 10 行

Question

I have a file and it contain a thousands values so i wont to read only the first 10 and the last 10 values

So I used v.readline() And v.read() but it didn't give me the solution

Answer 1

Iterate over the file using next function.

with open("file") as f:
    lines = [next(f) for x in range(10)]

Answer 2

Simply printing:

res=[]
with open('filename.txt') as inf:
    for count, line in enumerate(inf, 1):
        res.append(str(count))
for r in range(10):
    print(res[r])
for r in range(count-10,count):
    print(res[r])

Alternatively, this saves the output as variable 'result':

res=[]
result=''
with open('filename.txt') as inf:
    for count, line in enumerate(inf, 1):
        res.append(str(count))
for r in range(10):
    result = result + '\n' + res[r]
for r in range(count-10,count):
    result = result + '\n' + res[r]
print(result)