I started this as a joke among friends, telling that converting numbers to other integer bases is for n00bs, while an actual coder at least converts numbers to more complex bases like [pi (or π or however you wish to spell it in your language)](http://en.wikipedia.org/wiki/Pi), so they dared me proving I was better.

And I did it in few hours, discovering that what I started as a joke actually has [some math ground and application (particularly the conversion to base pi, it seems)](http://en.wikipedia.org/wiki/Non-integer_representation).

That said, now I am daring you to do the same, that is to build a function so that it takes a **number** (any number, you are warned!) and optionally the **number of decimals** (default: 0) and a **base** (default: pi), returning the proper conversion **as a string**:

#Note
In Java there is no easy way with optional parameters so all three parameters will be given; the same in C# because, as of now, the used version is not known. 

```python
converter(13) #returns '103'
converter(13,3) #returns '103.010'
converter(-13,0,2) #returns '-1101'
```

I know most of the world uses a comma as a [decimal mark](http://en.wikipedia.org/wiki/Decimal_mark), but as English language and culture are *de facto* the Esperanto of us coders, we will stick to our common glorious traditions and uses, adopting the trivial dot (".") as decimal separator; if the absolute value of the result is <1, you have of course to put one (and only one) leading 0 before the decimal separator.

Finally, you may assume that decimals if provided will always be >= 0 and that no test base will be smaller than 2 (because, you know, converting to base 1 is pretty lame) or greater than 36; as usual, for digits greater than 9 you can use uppercase alphabet letter, so your base of numeration is going to be: '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'.

That is my first 3-languages-kata, so I count on you all to give me extensive feedback, no matter how harsh it may sound, so to improve myself even further :)

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

def _disabled_input(*args, **kwargs):
    raise RuntimeError("input() is disabled in callable mode")
builtins.input = _disabled_input

ns = {"__name__": "__judge__"}  # prevent if __name__ == "__main__" blocks
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = "from math import pi\ndigs='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'\n\ndef converter(n, decimals=0, base=pi):\n    neg=''\n    ans=''\n    if n<0:\n        neg='-'\n        n=-n\n    for i in range(20,-20,-1):\n        if i==-1-decimals: break\n        if i==-1: ans+='.'\n        d=int(n /(base**i))\n        ans+=digs[d]\n        n-=d*base**i\n    while len(ans)>1 and ans[0]=='0' and ans[1]!='.': ans=ans[1:]\n    return neg+ans"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'converter'
if _fn_name:
    if "Solution" in ns:
        try:
            _obj = ns["Solution"]()
            if hasattr(_obj, _fn_name):
                _target = getattr(_obj, _fn_name)
        except Exception:
            _target = None
    if _target is None and _fn_name in ns and callable(ns[_fn_name]):
        _target = ns[_fn_name]
# Fallback: if there's exactly one user-defined function, use it
if _target is None:
    _cands = [v for k, v in ns.items() if callable(v) and getattr(v, "__module__", "") in ("__judge__", "__main__")]
    _user_funcs = [c for c in _cands if getattr(c, "__name__", "").startswith("_") is False]
    if len(_user_funcs) == 1:
        _target = _user_funcs[0]
if _target is None:
    raise RuntimeError(f"Could not resolve callable '{_fn_name}'")

_raw = sys.stdin.read().strip()
if _raw:
    _parsed = json.loads(_raw)
    if isinstance(_parsed, dict):
        _kwargs = _parsed.get("kwargs", {})
        _args = _parsed.get("args", [])
    else:
        _args, _kwargs = _parsed, {}
else:
    _args, _kwargs = [], {}
if not isinstance(_args, (list, tuple)):
    _args = [_args]
_res = _target(*_args, **_kwargs)
try:
    sys.stdout.write(repr(_res) + "\n")
except Exception:
    pass

```

Measured memory_bytes: 5798