""" Do single parameter math calculations with prompting
optionally converting degrees to radians"""

import math
try:
    input = raw_input
    # Python 2, input is replaced by raw_input like in Python 3
except:
    # no raw_input -> Python 3, input has correct definition -> do nothing
    pass

lookup = dict((func,math.__dict__[func])
              for func in math.__dict__
              # let's take out special __ starting functions
              if not func.startswith('__'))

while True:
    a = input("""
Enter function or
empty input to quit
? for list of functions:
""").lower()
    try:
        func = lookup[a]
    except KeyError:
        if not a:
            break
        elif a == '?':
            print('Available functions are:\n\t'+'\n\t'.join(lookup)+'\n')
        else:
            print("%r is not a legal function choice!" % a)
    else:
        if  hasattr(func, '__call__'):
            print('\n%s\n' % func.__doc__)
            try:
                args = input('Give parameter for %s: ' % a)
                if args:
                    args = args.split(',')
                    args = [float(arg) if '.' in arg else int(arg) for arg in args]
                    if 'radians' in func.__doc__:
                        args = args if input('Convert degrees to radians (Y/n)?').lower().startswith('n') else map(math.radians, args)
                    print (func(*args))
                else:
                    # function without parameters
                    print(func())
            except ValueError as e:
                print(e)
            except TypeError:
                print('Wrong number of parameters for %s' % a)
        else:
            print('Variable %r has value %s' % ( a, func))