Python：如何添加特定字符作为将列表转换为字符串以区分列表中的最后一项？

Question

I want to transform a list to a string including the square brackets and comma and then concatenate with another string.

Input:
    list1 = [1, 4, 3, 2, 5]
    str1 = 'is a list.\n'

Expected output:
    [1, 4, 3, 2, 5] is a list.

What I'm trying is like this:

path = [1, 4, 3, 2, 5]
str1 = 'is a list.\n'
ss = '['
for item in path:
    ss += str(item) + ', '
ss += '] ' + str1
print(ss)

But this results in the following output:

[1, 4, 3, 2, 5, ] is a list.

How to prevent the last comma ',' from generating as the process of transform?

I'm considering to take a specific process based on whether the item is the last one in the list.

But how can I know it?

Or else is there any other solution?

Really appreciate!

Answer 1

Print function uses the __str__ or __repr__ magic method of objects to render them. Knowing that you can do either:

print(path, "is a list.")

Or with string formatting:

print(f"{path} is a list.")

Answer 2

This is bad Approah:

path = [1, 4, 3, 2, 5]
str1 = 'is a list.\n'
ss = '['
for i in range(len(Path)):
    if i != (len(path)-1):
        ss += str(path[i]) + ', '
    else:
        ss += str(path[i])
ss += '] ' + str1
print(ss)

A good Approach is using f-Strings.

print(f"{path} is a list.\n")

if u doesn't like f-strings then

print("{} is a list.\n".format(path))