在python中读取文件的前N行
问题描述：
我们有一个大的原始数据文件，我们希望修剪到指定的大小。
我有经验的.net c＃，但是希望在python中做到这一点，以简化和消除兴趣。
We have a large raw data file that we would like to trim to a specified size. I am experienced in .net c#, however would like to do this in python to simplify things and out of interest.
python中的文本文件的前N行？
正在使用的操作系统是否对实现有任何影响？
How would I go about getting the first N lines of a text file in python? Will the OS being used have any effect on the implementation?
感谢：）
答
with open("datafile") as myfile:
head = [next(myfile) for x in xrange(N)]
print head
这是另一种方式
from itertools import islice
with open("datafile") as myfile:
head = list(islice(myfile, N))
print head