Is there a way to convert a string to a method in python?

Question

string = 'eggs, Spam, and eggs'
x = 'string.capitalize()'
print (x)
? print(method(x))

I know I could just
print (string.capitalize())
But I want to apply a bunch of different methods to different strings without having to type it over and over.
a = 'casefold'
x = 'string.' + a + '()'
?convert x to method type?

Answer 1

I mean, exec() and eval() could be used, but I suggest strongly against that as exec() and eval() will evaluate anything (such as mass file deletion).

Maybe use a lambda expression instead:

x = lambda x: x.capitalize()
str = "hello"
print(x(str))

Output:

Hello

Answer 2

You need to be very very careful in any "real" code when using eval/exec, if there is any doubt or lack of control over the args being passed to those functions, in particular if user input is involved. This is a classic security concern... having your code execute arbitrary commands fed into it is a Bad Thing. So just make sure that eval is only operating on internally hard-coded arguments that you choose and understand.

Answer 3

What @Eric said.

About that None, it's because the help() function is like a print() function, in that it prints the text to the screen. Because of that, the print() part of the:

print(exec('help(str.' + x + ')'))

line is not actually doing anything, and, as such, returns None. That line should be:

exec('help(str.' + x + ')')

instead, simply removing the print() function call.

Answer 4

Thank you both very much.

Answer 5

Learn Lisp 😂😂

Answer 6

Thank you. I actually found eval() about two minutes before I got your reply. I believe that is what I was looking for. But could you expound on why you think I shouldn't use it?
This is what I am working on.

https://code.sololearn.com/c4nOCGaSSI13/?ref=app

It is doing what I want, but I keep getting 'None' at the end of my output on one section.

Answer 7

Thank you. I actually found eval() about two minutes before I got your reply. I believe that is what I was looking for. But could you expound on why you think I shouldn't use it?
This is what I am working on.

https://code.sololearn.com/c4nOCGaSSI13/?ref=app

It is doing what I want, but I keep getting 'None' at the end of my output on one section.