Python int to binary string?

Question

Are there any canned Python methods to convert an Integer (or Long) into a binary string in Python?

There are a myriad of dec2bin() functions out on Google... But I

Answer 1

Summary of alternatives:

n=42
assert  "-101010" == format(-n, 'b')
assert  "-101010" == "{0:b}".format(-n)
assert  "-101010" == (lambda x: x >= 0 and str(bin(x))[2:] or "-" + str(bin(x))[3:])(-n)
assert "0b101010" == bin(n)
assert   "101010" == bin(n)[2:]   # But this won't work for negative numbers.

Contributors include John Fouhy, Tung Nguyen, mVChr, Martin Thoma. and Martijn Pieters.