How to print variable name?

[mayadob]

I want to calculate the lenght of a segment and then to print "The lenght of AB is 27 cm" for example.
In wich the name AB are the names of two variables - point A and point B (Actually A and B are vectors but the point is how to print their names, not how to operate with them)

And to be appliable in function.
Something like:

lenght(A,B)

[mayadob]

Could not finish editing the post (there was a time limit)
So I continue:

Something like:

def name(Whatever)#this is the function I'm looking for. Gives me the name of the variable. In this case - Whatever
  ???

def lenght(x,y)
  ...some calculations...
  print('The lenght of', name(x), name(y), 'is', ..the result of the calculations...)

And then to call lenght with A and B:

lenght(A,B)

The result should be:

The lenght of AB is 27 cm

[Larz60+]

length is len, not lenght
rather than 'something like' make an effort and actually try to get some working code.

[mayadob]

There is an almost working code.

def name(obj, callingLocals=locals()):
    for k, v in list(callingLocals.items()):
         if v is obj:
            nm = k
    print(nm)

It's not working properly in this case:

a=3
b=3
name(a)

The result is
b
(it shoul be a)

[perfringo]

I don't get it. First of all why, second of all what (yeah, it's Friday evening in my timezone)

x, y are function parameters/arguments not variable names. What names should be displayed length(2, 3) (assuming that there is no name pointing to values 2 and 3)?

With Python 3.8 anyone can have variable names very easily by using new f-string debugging feature {x=}.

Intended way of using it is something along those lines:

>>> def length(x, y):
...     return f'The length of {x=}, {y=} is {x+y}'
... 
>>> print(length(5, 10))
The length of x=5, y=10 is 15

So one can take advantage of this feature without any function and do something like this:

>>> x, y = 7, 42
>>> name_x_as_string = f'{x=}'.split('=')[0]
>>> name_y_as_string = f'{y=}'.split('=')[0]
>>> f'The length of {name_x_as_string}{name_y_as_string} is {x + y}'
'The length of xy is 49'

[mayadob]

Thank you.
I need to think over it.

[mayadob]

>>> x, y = 7, 42
>>> name_x_as_string = f'{x=}'.split('=')[0]
>>> name_y_as_string = f'{y=}'.split('=')[0]
>>> f'The length of {name_x_as_string}{name_y_as_string} is {x + y}'
'The length of xy is 49'

It might be something like this.

But still I need it to be in function. I want to call the function with variables like this:

def length(x,y):
    name_x_as_string = f'{x=}'.split('=')[0]
    name_y_as_string = f'{y=}'.split('=')[0]
    print(f'The length of {name_x_as_string}{name_y_as_string} is {x + y}')

a=5
b=3
length(a,b)

The result here is:

The length of xy is 8

It's not what I need. The result should be:

The length of ab is 8

Is it understandable?

[newbieAuggie2019]

The result should be:

The length of ab is 8

Hi!

I'm not sure what you want. Could it be this???:

def length(x,y):
    print(f"The length of 'ab' is {x + y}.")

a = 5
b = 3
length(a, b)

that produces the following output:

Output:
The length of 'ab' is 8.

All the best,

[mayadob]

Hi!

I'm not sure what you want. Could it be this???:

def length(x,y):
    print(f"The length of 'ab' is {x + y}.")

a = 5
b = 3
length(a, b)

that produces the following output:

Output:
The length of 'ab' is 8.

All the best,

What if I call it with:

length(c, d)
length(e,f)

Every time the result should be

The length of 'ab' is ...

While it has to be:

The length of 'cd' is ...

and

The length of 'ef' is ...

[ichabod801]

As perfringo points out, that's not really possible. Once it's in the function, it's not a and b (or c and d) anymore. It's x and y. If you want the name to be available, you are going to have to store it explicitly. So if a and b are two dimensional points, you might be storing them as tuples: (2, 3) and (4, 5). To get the name out, you need to store it with the tuple. You could do a longer tuple: ('A', 2, 3) and ('B', 4, 5). You could do a dictionary: {'name': 'A', 'coord': (2, 3)} and {'name': 'B', 'coord': (4, 5)}. You could do a named tuple or even a full fledged class. But somehow you need to store the name.