What condition caused this True?

[majorjohnusa]

You seem to be confusing English and Python, my friend. The basic idea in Python is that anything that follows if/elif/else are statements that are evaluated to True or False (I'm sure this isn't 100% true all the time but this should suffice for our example here). This means that "if True" does not mean literally "if [blank] is True then...", instead it means "if True is True then...".

Here:

#if True is True (True == True, so this is executed)
if True:
  print("1")
#else if True is True (True == True, but the previous statement always executes so this does not run)
elif True:
  print ("2")
#all other cases (will never happen, same reason)
else:
  print("3")

Now, the second example:

#If not True (not True == False) is True (False != True, so this does not run)
if not True:
  print("1")
#If not False (not False == True) is True (True == True, so this runs)
elif not False:
  print ("2")
#all other cases, this never runs, again
else:
  print("3")

Thank you for your reply. Now this makes sense to me, True or False is simply the condition of whether a command will be executed.

[venquessa]

Just to add one little thing, because it bugs me when I see it.

There is no need to directly compare things to "True". For example, none of these are "proper" although they will compile and are technically valid.

if thisThing == True:

All you need is:

if thisThing:

if thisThing not True:

All you need is:

if not thisThing:

On this one:

while True:

There is controversy. This creates what is called a "unbounded loop". It presents a possibility it will never exit. You could have this:

while True:
    if someThing:
        break;

A lot of coding practices and static analyzers will flag this as bad practice as if whatever is providing "someThing" goes wrong the while creates an infinite, run forever, loop.

In this case it's easy to fix, eg:

while not someThing:

If you want a "nearly" infinite loop and avoid "best practice" warnings, you can use the "while running" pattern.

running = True

while running:
    try:
        stuff
        otherstuff
    except Exception as e:
        log_exception()
        running = False

Hope this helps.

[ThomasL]

while True:
    if someThing:
        break;

And if you don´t use ; in python code anymore you become a True pythonista.

[perfringo]

As always I suggest before and above all to get acquainted with documentation: Truth Value Testing or typing help('TRUTHVALUE') into interactive interpreter. Maybe also help('for') and help('while') if you are into it.

[venquessa]

while True:
    if someThing:
        break;

And if you don´t use ; in python code anymore you become a True pythonista.

Damn, caught red handed :)

I'm a Java programmer by day. My own python code is also littered with someVariableName and PyCharm keeps whining at me :)

I'm only human not a python-esk god. :D