Python-сообщество

 my_str = 'строка'
my_list = list(my_str)
print(my_list)

[12, 45]

['1', '2', ',', ' ', '4', '5']

[1, 2, ',', ' ', 4, 5]

 from ast import literal_eval
in_str = '[12, 45]'
result = literal_eval(in_str)
print(result, type(result))
>>>
[12, 45] <class 'list'>

  
>>> int('a')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: 'a'
>>> 0 + 'a'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for +: 'int' and 'str'
>>>

  
>>> try:
...     int('a')
... except ValueError:
...     print('It\'s not a number')
... 
It's not a number
>>>
>>> try:
...     0 + 'a'
... except ValueError:
...     print('It\'s not a number')
... 
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
TypeError: unsupported operand type(s) for +: 'int' and 'str'
>>>