Python Lambda in a loop [duplicate]

Answer 1

Alternatively, instead of lambda, you can use functools.partial which, in my opinion, has a cleaner syntax.

Instead of:

for d in directorys:
    self.command["cd " + d] = (lambda d=d: self.root.change_directory(d))

it will be:

for d in directorys:
    self.command["cd " + d] = partial(self.root.change_directory, d)

---

Or, here is another simple example:

numbers = [1, 2, 3]

lambdas = [lambda: print(number) 
           for number in numbers]
lambdas_with_binding = [lambda number=number: print(number) 
                        for number in numbers]
partials = [partial(print, number) 
            for number in numbers]

for function in lambdas:
    function()
# 3 3 3
for function in lambdas_with_binding:
    function()
# 1 2 3
for function in partials:
    function()
# 1 2 3