Type conversation of objects in python-CodePudding

How to write a function on python that accepts two objects in input and gives on output minimal type which both of objects can be presented? For example, if we have [1, 2, 3] and 2 we can convert it to str, if we have "Hi" and 1.2 we can convert it to str, if we have True and 1.2 we can convert it to float and so on.

CodePudding user response：

All objects in Python can be converted to strings, even user defined class instances.

>>> class Test:
    pass

>>> t = Test()
>>> str(t)
'<__main__.Test object at 0x0000015315891730>'
>>> str(1)
'1'
>>> str(True)
'True'
>>> str([1, 2, 3])
'[1, 2, 3]'
>>>

This is because they have a __str__ function that is automatically defined even if you don't define it.

Edit: You can do it like this (pardon the ugly code)

def leastConversions(first, second):
    type_casts = [str, int, float, tuple, list, dict]
    times = {}
    for _type in type_casts:

        if not isinstance(first, _type):
            times[_type] = 0
            try:
                if not isinstance(first, _type):
                    temp = _type(first)
                    times[_type]  = 1
            except TypeError:
                del times[_type]
                continue
            
            try:
                if not isinstance(second, _type):
                    temp = _type(second)
                    times[_type]  = 1
            except TypeError:
                del times[_type]
                continue
    return min(times, key = lambda k: times[k])

CodePudding user response：

When compare int and float answer is int but should be float

def type_convertion(first, second):
    data_types = [int, float, tuple, list, str]
    times = {}
    for _type in data_types:
        times[_type] = 0
        try:
            if isinstance(_type(first), _type):
                times[_type]  = 1
        except TypeError:
            del times[_type]
            continue
        try:
            if isinstance(_type(second), _type):
                times[_type]  = 1
        except TypeError:
            del times[_type]
            continue
        return times.keys()