隨機檔案訪問使用 mmap
使用 mmap
模組允許使用者通過將檔案對映到記憶體中來隨機訪問檔案中的位置。這是使用普通檔案操作的替代方法。
import mmap
with open('filename.ext', 'r') as fd:
# 0: map the whole file
mm = mmap.mmap(fd.fileno(), 0)
# print characters at indices 5 through 10
print mm[5:10]
# print the line starting from mm's current position
print mm.readline()
# write a character to the 5th index
mm[5] = 'a'
# return mm's position to the beginning of the file
mm.seek(0)
# close the mmap object
mm.close()