text
stringlengths
1
81
start
float64
0
10.1k
duration
float64
0
24.9
glance
1,425.919
3.401
rather complicated here let's look up at
1,426.96
6.64
sys.rgv i'm going to bracket one here so
1,429.32
8.2
clearly sys.rv bracket one
1,433.6
7.92
is storing dav id but it's one in the
1,437.52
6.08
past when we looked at loops recall that
1,441.52
4.48
we said that they were zero indexed that
1,443.6
4.48
is the first element is zero the next
1,446
4.799
element is one this next element is two
1,448.08
5.28
and so forth and yet here i am treating
1,450.799
4.24
it as though my name is at the start of
1,453.36
4.24
the list one well let me ask this
1,455.039
3.681
question
1,457.6
5.439
what is probably in cis.rgv of zero
1,458.72
8.8
what is probably insist dot argv of zero
1,463.039
7.12
the very first element actually in that
1,467.52
5.759
list oh yeah i think
1,470.159
5.361
it's like in c
1,473.279
4.321
the name of program
1,475.52
4.08
indeed it's indeed like in c in other
1,477.6
4.319
languages the name of the program well
1,479.6
4.72
if we consider what it was i typed i
1,481.919
3.921
certainly typed python because that's
1,484.32
3.12
the name of my interpreter and we don't
1,485.84
3.12
really need to know that because we're
1,487.44
3.76
using python itself but after that i did
1,488.96
4.719
type two things i typed name dot pi as
1,491.2
4.4
i've done so many times anytime i want
1,493.679
3.681
python to interpret a program i've
1,495.6
3.679
written and it turns out by convention
1,497.36
5.04
what python does is it stores in sys.rgv
1,499.279
5.361
the name of the file that you're
1,502.4
5.12
executing or interpreting followed by
1,504.64
5.2
any number of other words that you typed
1,507.52
4.399
so all this time we could have been
1,509.84
3.68
accessing the name of the program which
1,511.919
3.36
frankly isn't all that interesting but
1,513.52
4
we can also now access words that are
1,515.279
5.041
typed after that prompt as well
1,517.52
5.6
but of course if i don't type anything
1,520.32
3.839
in
1,523.12
2.799
what might happen here this might be
1,524.159
3.201
naive of me to assume that there's
1,525.919
3.12
always going to be something at location
1,527.36
4.24
1 in sys.rgv let me go ahead and try
1,529.039
5.52
this python name dot pi and no i'm not
1,531.6
4.64
giving you my name because at this point
1,534.559
3.681
i might not even know that you want my
1,536.24
4.4
name to be typed so let me hit enter now
1,538.24
4.72
and uh uh-oh we see now an error a
1,540.64
4.56
so-called exception in python this one's
1,542.96
5.04
a new one this one's an index error that
1,545.2
5.92
elaborates list index out of range and
1,548
4.4
turns out this is actually one of the
1,551.12
3.36
most common mistakes in programming
1,552.4
4.8
whether using a list in python or arrays
1,554.48
4.88
or vectors in other languages is to try
1,557.2
4.32
to access some element that does not
1,559.36
4.319
exist you try to go too far to the left
1,561.52
4.159
or you try to go too far to the right in
1,563.679
3.201
this
1,565.679
3.6
in this object that is just a list of
1,566.88
4.96
some values so of course the mistake
1,569.279
4.321
here is that i'm assuming there's going
1,571.84
3.839
to be something at location one when
1,573.6
4.4
really it's location zero that's the
1,575.679
4.401
only one that has a value but fixing
1,578
4.159
this is not going to amount to doing
1,580.08
4.32
bracket zero because now if i go ahead
1,582.159
4.4
and rerun this program with no other
1,584.4
4.8
words after name.pi it says hello my
1,586.559
4.961
name is name.pie which is fine if we're
1,589.2
4
making a name tag for the program but
1,591.52
3.68
that's not of course what my goal here
1,593.2
4.64
is instead so if the fix is not just to
1,595.2
4.8
change the one to a zero
1,597.84
5.68
how else might i handle this error
1,600
6.08
how else might i handle this error
1,603.52
4.399
this index error that happens if the
1,606.08
4
user just doesn't remember to or doesn't
1,607.919
4.321
know to type their actual name at the
1,610.08
3.44
prompt
1,612.24
3.36
we could always put an exception into
1,613.52
4
the program saying
1,615.6
4.959
if there is um if there's nothing at
1,617.52
4.72
location one
1,620.559
4
we just come out to say okay we haven't
1,622.24
4.4
got a parameter or something but if
1,624.559
3.921
there is you continue along with the
1,626.64
3.12
program
1,628.48
3.28
perfect so if i might simplify we can
1,629.76
4.24
try to execute this line of code except
1,631.76
3.6
if there's an error we'll deal with it
1,634
3.919
in some other way now ideally and once
1,635.36
4.24
i'm a strong enough programmer i would
1,637.919
3.601
have anticipated this and written the
1,639.6
4
following code from the get-go but when
1,641.52
3.039
you're learning it's certainly
1,643.6
2.559
reasonable to see an error oh i didn't
1,644.559
3.521
realize i should detect that and then go
1,646.159
3.601