This is the implementation of codecs.Streamwriter.writelines for all
Python versions that I've checked:
def writelines(self, list):
""" Writes the concatenated list of strings to the stream
using .write().
"""
self.write(''.join(list))
This may be a problem if the 'list' parameter is a generator. The
generator may be returning millions of values, which the join will
concatenate in memory. It can surprise the programmer with large
memory use. I think join should only be used when you know the size of
your input, and this method does not know this. I think the safe
implementation of this method would be:
def writelines(self, list):
""" Writes the concatenated list of strings to the stream
using .write().
"""
write = self.write
for value in list:
write(value)
If a caller knows that it's input list would use a reasonable amount
of memory, it can get the same functionality as before by doing
stream.write(''.join(list)).