Is seems that the mmap interface only supports readline(). If I try to iterate over the object I get character instead of complete lines.
What would be the "pythonic" method of reading a mmap'ed file line by line?
import sys
import mmap
import os
if (len(sys.argv) > 1):
STAT_FILE=sys.argv[1]
print STAT_FILE
else:
print "Need to know <statistics file name path>"
sys.exit(1)
with open(STAT_FILE, "r") as f:
map = mmap.mmap(f.fileno(), 0, prot=mmap.PROT_READ)
for line in map:
print line # RETURNS single characters instead of whole line
The most concise way to iterate over the lines of an mmap
is
with open(STAT_FILE, "r+b") as f:
map_file = mmap.mmap(f.fileno(), 0, prot=mmap.PROT_READ)
for line in iter(map_file.readline, b""):
# whatever
Note that in Python 3 the sentinel parameter of iter()
must be of type bytes
, while in Python 2 it needs to be a str
(i.e. ""
instead of b""
).