Coding Computing Coach

Making Python simple for you, by exploring the fundamentals.

Tips and explanations to become code-literate in this AI age.

Building @PythonResources

[Coding Computing Coach @CodingComputing]

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Ongoing series of posts, see README at:

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[Coding Computing Coach @CodingComputing]

@PythonPr Answer: A

Solution: x.insert(2, 0) modifies x.

It inserts the item 0 at index 2.

What happens to the current items at index 2 and beyond in x?

They get shifted to the right.

So, x gets modified to
[5, 6, 0, 7, 8]

that's what is printed, hence Option A is correct.

[Coding Computing Coach @CodingComputing]

@PythonDvz Strings in python are immutable.

That means, once a string object is created, it cannot be modified.

Here we are creating the string and trying to make a change to it.

But that gives an error because strings aren't mutable.

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: 17

Solution: x is 2 and y is 3.

z is assigned the expression
x**y + y**x
ie
3**2 + 2**3

There are 2 operations here: ** that denotes exponentiation, and + for addition.

** has higher precedence, so it's performed first.
3**2 is 9
2**3 is 8

9+8 is 17, that's printed.

[Coding Computing Coach @CodingComputing]

@driscollis 1 and 2 on the regular!

[Coding Computing Coach @CodingComputing]

@PythonDvz NameError.

We are trying to access x, but we have never defined what x is.

Since python doesn't know what x is, it puts up an error. Specifically a NameError.

[Coding Computing Coach @CodingComputing]

@kmcnam1 Not surprising to see people saying this.

Especially when there are AI-integrated fridges.

[Coding Computing Coach @CodingComputing]

@RealBenjizo Answer: B

Solution: The function is the tricky part, let's zoom in on that.

The function call passes the argument d to modify_dict.

But modify_dict doesn't "modify" d.

Rather, it gives the name d to something else (dictionary with grandma).

And, that changed d is just a

+

[Benjamin Bennett Alexander @RealBenjizo]

Python Question

What is the output of this code and why?

[Coding Computing Coach @CodingComputing]

@RealBenjizo local variable.

And then we return d. But that returned value is never saved.

So, the d in the main program remains unchanged.

[Coding Computing Coach @CodingComputing]

@RealBenjizo Answer: B

Solution: The function is the tricky part, let's zoom in on that.

The function call passes the argument d to modify_dict.

But modify_dict doesn't "modify" d.

Rather, it gives the name d to something else (dictionary with grandma).

And, that changed d is just a

+

[Coding Computing Coach @CodingComputing]

@RealBenjizo Answer: a. Error

Solution: x is a tuple.

Tuples are immutable, ie, you cannot change it after it is created.

In the function call to func, the argument is the tuple.

However, func tries to modify the index 0 value of this tuple.

This gives error because tuples are immutable.

[Benjamin Bennett Alexander @RealBenjizo]

Python Question:

Let's see who can explan this better.

What is the output of this code?

[Coding Computing Coach @CodingComputing]

@RealBenjizo Answer: a. Error

Solution: x is a tuple.

Tuples are immutable, ie, you cannot change it after it is created.

In the function call to func, the argument is the tuple.

However, func tries to modify the index 0 value of this tuple.

This gives error because tuples are immutable.

[Coding Computing Coach @CodingComputing]

@akshaymarch7 Writing code with correct syntax is not the bottleneck.

The understanding the requirements and formulating a sound plan is more important than ever.

[Coding Computing Coach @CodingComputing]

Indexing starts from 0 for the leftmost item.

The more you increase, the rightwards you go.

BUT there is a negative indexing feature.

The negative index starts from -1 from the rightmost item.

The more you decrease, the leftwards you go.

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: 3

Solution: As we know, indexing starts from 0, from the leftmost item.

However, python provides this feature of negative index, which makes it easy to obtain items from the right.

a[-1] refers to the last (rightmost) item of the list a.

Thus, here it is 3.

[Coding Computing Coach @CodingComputing]

Tuples are the immutable cousins of lists.

[Coding Computing Coach @CodingComputing]

@PythonPr False.
`a` is a list.

tuple(a) produces a tuple from `a`.
So, it has the same items, in the same order.
But within a tuple as the container.

As the containers don't match (list vs tuple),
the comparison gives False.

[Coding Computing Coach @CodingComputing]

In python, * doesn't just multiply...

[Coding Computing Coach @CodingComputing]

@PythonDvz Answer: C

a is a str & b is an int.

It seems impossible to multiply them using the * operator.

But the * operator does different things for different operand types.

For str and int, the * operator repeats the str, int times.
'5' * 3 repeats the string thrice, ie, "555"

[Coding Computing Coach @CodingComputing]

@PythonDvz Answer: C

a is a str & b is an int.

It seems impossible to multiply them using the * operator.

But the * operator does different things for different operand types.

For str and int, the * operator repeats the str, int times.
'5' * 3 repeats the string thrice, ie, "555"