Defining bacon and eggs.

Question

def spam(a):
def eggs():
a[:] = [5]
def bacon():
a[0] += 1
eggs()
bacon()
return a[0]
print(spam([2]))

Output: 6

HonFu was kind enough to give me some help, but I'm still a bit lost.
-HF pointed out that both "eggs" and "bacon" are being defined in "spam".
-So print(spam([2])) means to print "2"? So is it number to += 1 or a[:] = [5], which is a dictionary but still no idea where to go from there.
-Any additional help appreciated:).

Answer 1

def spam(a):
def eggs():
a[:] = [5]
def bacon():
a[0] += 1
eggs()
bacon()
return a[0]
print(spam([2]))

def spam(a):
def eggs():
a[:] = [5,11,15]
def bacon():
a[2] += 1
eggs()
bacon()
return a[2]
print(spam([100]))

Thanks Diego, I reworked the code. The number in print(spam([100])) could be anything as its changed to 5 when list [a:] = 5 runs.

Then I added extra numbers to the list. You can now run it and by changing return a[] AND a[2] += 1 you can add one (or any other number) to index [0:2].

Answer 2

The code you're showing us is equal to this one.

a = [2]
a[:] = [5]
a[0] += 1
print(a[0]) # 6

"a[:] = 5" doesn't create a dictionary but simply modifies the value of the list "a".

a = [1, 2, 3]
a[:] = 5
print(a) # [5]

a = ["spam", "eggs"]
a[:] = 5
print(a) # [5]

Then, "a[0] += 1" adds a one to the first element of list "a" (5+1 == 6). Thus, 6 is printed.

Answer 3

Thanks, Diego. Why did they write "a[:] = 5"? Why not just "a =5"? I know that closed square brackest mean list, not dictionary (thanks for pointing out my error:)). Are they saying #in original a=[1,2,3] from the 0 index to the last index delete all and assign a new value of 5? Is that what the colon means here (your code makes a lot more sense than theirs:)).

Answer 4

My mistake. It was supposed to be "a[:] = [5]". Edited my post.

That said, "a[:] = 5" doesn't actually delete the previous values of "a" (they still exist somewhere in the universe), it just reassigns the list to another value.

About their code, I suppose it's confusing on purpose. Perhaps it was meant to make you think and ask yourselve questions like these (which is good, I like that).

Answer 5

But to read this code out loud it would go#print-spam-2, which becomes def eggs(2):, which iteratws to [5], and then whose value is added a 1 to? Am I reading that right in my head?

Thanks. This one was a lu-lu!