Let's say I have the following code:
string = "XxXxXx"
print(string.lower())
print(string.upper())
How could I use a list instead along the lines of:
string = "XxXxXx"
list = [lower(), upper()]
for i in list:
print(string.i)
Obviously the code above does not work at all and the problem I'm working on is way more complicated. But if I could make the example above work, it would really take care of my problem!
Functions (and methods) are first class objects in python. You can therefore store them in a list just like you would anything else.
If you want to be able to apply the functions to arbitrary strings, use the unbound function objects in the class:
string = "XxXxXx"
func_list = [str.lower, str.upper]
for i in func_list:
print(i(string))
If you want to only apply the functions to your special string, you can store the bound methods in a list instead:
string = "XxXxXx"
func_list = [string.lower, string.upper]
for i in func_list:
print(i())
In both cases, the () operator is what calls the function. The function name by itself is a reference to the object. In the first case, the . operator does not do anything surprising. In the second case, since you invoke it on an instance of a class, it binds the function object in the class to the instance, creating a bound method that has an implicit self argument.
listis a bad variable name since it shadows the builtinlisttype. In example code it's not a big problem, just a bit confusing, but in more involved code, it's better to use a more descriptive name, or at least something likeLorlst. Cf. TypeError: 'list' object is not callable.