If you need unary numeral system, you can convert an integer like this:
>> n = 6
>> '1' * n
'111111'
If you need a support of negative ints you can just write like that:
>> n = -6
>> '1' * n if n >= 0 else '-' + '1' * (-n)
'-111111'
Zero is special case which takes an empty string in this case, which is correct.
>> n = 0
>> '1' * n if n >= 0 else '-' + '1' * (-n)
''