how to concatenate a string and a variable and assign a value in it in python

Question

Is there anyway to assign value in concatenated variable?

I want to concatenate and assign a value in it.

for i in range (5):
    'serial_' + str(i) = i+5

that showing SyntaxError: can't assign to operator

possible duplicate: https://stackoverflow.com/questions/1373164/how-do-i-create-a-variable-number-of-variables — SuperShoot, Nov 04 '18 at 03:23

Mayank Porwal · Answer 1 · 2018-11-02T07:37:49.187

1

If I understand correctly,

d = {}
In [898]: for i in range (5):
     ...:    d[ ('{}' + str(i)).format('serial_')] = i+5


In [899]: d
Out[899]: {'serial_0': 5, 'serial_1': 6, 'serial_2': 7, 'serial_3': 8, 'serial_4': 9}

Let me know if this is what you want.

edited Nov 02 '18 at 07:37

answered Nov 02 '18 at 07:23

Mayank Porwal

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It is only concatenation. i want to use this(serial_5,serial_6...) as variable name. – Chandan Kumar Nov 02 '18 at 07:31
well this will work but i also want to know is there other way to do this without dict. like a simple variable (serial_0 =5) – Chandan Kumar Nov 02 '18 at 07:47

kalehmann · Accepted Answer · 2018-11-02T08:00:42.247

It is possible to add variables with concatenated names in the global/local symbol table using the globals and locals built-in functions:

>>> for i in range (5):
...     global()['serial_' + str(i)] = i+5
... 
>>> serial_0
5
>>> serial_3
8

However according to the documentation, changing the dictionary returned by locals may have no effect to the values of local variables used by the interpreter.

Furthermore since modifying the global symbol table is not considered a good practice, I recommend you to use a dictionary to store your values as suggested by Mayank Porwal as this will result in cleaner code:

>>> d = {f'serial_{i}' : i + 5 for i in range(5)}
>>> d
{'serial_0': 5, 'serial_1': 6, 'serial_2': 7, 'serial_3': 8, 'serial_4': 9}

how to concatenate a string and a variable and assign a value in it in python

2 Answers2