Python: right way to build a string by joining a smaller substring N times

Question

What is the right "pythonic" way to do the following operation?

s = ""
for i in xrange(0, N):
    s += "0101"

E.g. in Perl it would be: $s = "0101" x $N

Answer 1

The most Pythonic way would be

s = "0101" * N

Other methods include:

• use StringIO, which is a file-like object for building strings:

  from StringIO import StringIO
  

• use "".join; that is

  `"".join("0101" for i in xrange(N)`
  

• use your algorithm. In an unoptimised world this is less good, because it is quadratic in the length of the string. I believe recent versions of Python actually optimise this so that it is linear, but I can't find a reference for that.

Answer 2

Nearly the same as Perl:

"0101" * N