Question: I would like to know how to do an equivalent of the range function in python, but with the ability to specify the base number. For example:

```
countUp(start=0, end=1010, base=2)
countUp(start=0, end=101, base=3)
countUp(start=0, end=22, base=4)

```

Example output for base 2 counting:

```
[0, 1, 10, 11, 100, ...]

```

Is there a function I'm missing that does this? Or what could I do instead?

Answer: 
You can do it with a custom iterator:

I took the iterater code from [here](https://stackoverflow.com/a/24377/4194964) and the base conversion from [here](https://stackoverflow.com/a/2267446/4194964)

```
import string
class BaseRange:
    def __init__(self, low, high, base):
        digs = string.digits + string.letters
        self.current = low
        self.high = high
        self.base = base
    def __iter__(self):
        return self
    def next(self):  # Python 3 requires this to be __next__
        if self.current > self.high:
            raise StopIteration
        else:
            self.current += 1
            return self.int2base(self.current - 1, self.base)
    def int2base(self, x, base):
        if x < 0: sign = -1
        elif x == 0: return digs[0]
        else: sign = 1
        x *= sign
        digits = []
        while x:
            digits.append(digs[x % base])
            x /= base
        if sign < 0:
            digits.append('-')
            digits.reverse()
        return ''.join(digits)

```

A Few Example runs produces:

```
>>> for c in BaseRange(0, 10, 2):
    print(c)

0
1
01
11
001
101
011
111
0001
1001
0101
>>> for c in BaseRange(0, 10, 3):
    print(c)

0
1
2
01
11
21
02
12
22
001
101

```
You can not crate integers with special based, but you can create your expected numbers in a specified base in string :

```
def my_range(start,end,base,step=1):

    def Convert(n,base):
       string = "0123456789ABCDEF"
       if n < base:
          return string[n]
       else:
          return Convert(n//base,base) + string[n%base]
    return (Convert(i,base) for i in range(start,end,step))

```

Demo:

```
print list(my_range(4,20,2))
['100', '101', '110', '111', '1000', '1001', '1010', '1011', '1100', '1101', '1110', '1111', '10000', '10001', '10010', '10011']

```

Note that the passed string `string = "0123456789ABCDEF"` to function will works till base `16`, if want to calculate greater based you can use more letters.