NoneType List

[Weatherby,Gerard]

Just use the addition operator:

a = [1,2]

a = a + [3,4]

a is now [1, 2, 3, 4]

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Goran Ikac <goranikac65 at gmail.com>
Date: Saturday, December 31, 2022 at 1:53 AM
To: python-list at python.org <python-list at python.org>
Subject: NoneType List
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Happy New Year, everybody!
I'm new in the Python List, new in Python world, and new in coding.
A few days (weeks?) ago, I faced a problem trying to write a program for an
exercise. I asked for help and nobody answered.
In the meantime, I found a part of the solution, but a part still remains a
mystery for me. Please run this small snippet, and help.
Thanks

a = [1, 2]
print()

print("a ==", a)
print("type(a) is", type(a))

b = a.append(3)
print("\nb =", "a.append(3)")
print("b ==", b)
print("type(b) is", type(b))

c = ['1', '2']
print("\nc ==", c)
print("type(c) is", type(c))

d = c.append('3')
print("\nd =", "c.append('3')")
print("d ==", d)
print("type(d) is", type(d))

"""
I mean: why b = a.append(something) is the None type, and how to make a new
list
that contains all the items from a and some new items?
I wasn't able to solve it in a few hours :(
Now I know:
"""

crta = '='
print('\n', 4 * ' ', crta * (len('The solution:')), sep='')
print(3 * ' ', 'The solution:')
print(4 * ' ', crta * (len('The solution:')), sep='')
print('\nThe solution is the slice, an element of Python syntax that
allows')
print('to make a brand new copy of a list, or parts of a list.')
print('The slice actually copies the list\'s contents, not the list\'s
name:')

print()
a = [1, 2]
print("a ==", a)
print("type(a) is", type(a))

b = a[:]
print("\nb = a[:]")
print("b ==", b)
b.append(3)
print("\nb =", "b.append(3)")
print("b ==", b)
print("type(b) is", type(b))
print("\na ==", a)

print('But I still don't know why "b = a.append(something)" is the None
type.')
print('Is there anybody out there?!')
--
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