I am relatively new to coding and python and I am trying to wrap my head round some concepts. One I am struggling on is the split() function and why these two pieces of code produce two different outputs
y = ["hello\n", "world\n", "python\n"]
x = [line.strip() for line in y]
print(x)
and
y = ["hello\n", "world\n", "python\n"]
for line in y:
x = [line.strip()]
print(x)
The first piece of code produces an output of
['hello', 'world', 'python']
Whilst the second produces
['python']
Does anyone know why this is, as to me they should do the same thing by both producing an output of
['python']
thanks
Does anyone know why this is, as to me they should do the same thing by both producing an output of ['python'].
Your first code uses list comprehension which is used to create a sequence. It provides a concise way to create lists or sequence of elements.
Your second code is basically using a for loop just to get the last element of list y. for loop is used if you want to iterate through a sequence. However, you are also overwriting the variable x in each of your iteration and hence, when you come out of for loop, it will be pointing to the last element (i.e., ['python']). Try this:
for line in y:
x = [line.strip()]
print(x)
If you just want the last element of your list y and strip() it, you can also do that via:
x = [ y[-1].strip() ]
OR
If you want the list, then use your first code.
MORE INFORMATION
If you can change your second code to:
x = [ ]
y = ["hello\n", "world\n", "python\n"]
for line in y:
x.append(line.strip())
print(x)
Then both will print same output (i.e., ['hello', 'world', 'python']).