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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[Coding Computing Coach @CodingComputing]

@PythonPr Answer: 0 2 4 (on separate lines)

Solution: In this for-loop, the iteration happens over
range(3)

which is simply a sequence from 0 to 3 (excluding 3)
ie, 0, 1, and 2.

So, i gets the values 0, 1, and 2 in the 3 iterations.

In each iteration, (i*2) gets printed

When i=0,

+

[Python Programming @PythonPr]

Python Quiz: What is the Output?

[Coding Computing Coach @CodingComputing]

@PythonPr 0 is printed.

When i=1, 1*2=2 gets printed.

When i=2, 2*2=4 gets printed.

So, in the 3 iterations, the output is:
0
2
4

And the loop ends with that, so that is the output.

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: 0 2 4 (on separate lines)

Solution: In this for-loop, the iteration happens over
range(3)

which is simply a sequence from 0 to 3 (excluding 3)
ie, 0, 1, and 2.

So, i gets the values 0, 1, and 2 in the 3 iterations.

In each iteration, (i*2) gets printed

When i=0,

+

[Coding Computing Coach @CodingComputing]

@clcoding Answer: ** is python exponentiation operator. Mathematically, this is simply the "power" or "raised to".'

2 ** -1
is 2 raised to the power (-1),
ie, 1/2 which is 0.5

[Coding Computing Coach @CodingComputing]

@clcoding Answer: ** is python exponentiation operator. Mathematically, this is simply the "power" or "raised to".'

2 ** -1
is 2 raised to the power (-1),
ie, 1/2 which is 0.5

[Coding Computing Coach @CodingComputing]

Comparing numbers and strings

[Coding Computing Coach @CodingComputing]

@clcoding Answer: False

Solution: Let us compare the values on the sides of ==.

The right hand side is 77.

The left hand side is x*2, and x is "7", a string.

"7"*2 repeats the string "7" 2 times, giving "77".

But note that this isn't the number 77, it is a string.

That means,

+

[Python Coding @clcoding]

What will be the output of the following Python code?

x = "7"
print(x * 2 == 77)

[Coding Computing Coach @CodingComputing]

@clcoding "77" is a sequence of two characters, '7' and '7'

So, "77" is not the same as the number 77.

"77" == 77
works out False.

So, False is what gets printed.

[Coding Computing Coach @CodingComputing]

@clcoding Answer: False

Solution: Let us compare the values on the sides of ==.

The right hand side is 77.

The left hand side is x*2, and x is "7", a string.

"7"*2 repeats the string "7" 2 times, giving "77".

But note that this isn't the number 77, it is a string.

That means,

+

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: [5, 5, 5]

Solution: The value of x is [5].

Observe that it is a list with a single item, 5.

Now, what is x * 3?

How do you multiply a list with a number?

The answer is, python repeats the list.

So,
[5] * 3
is the items in the list [5], repeated 3 times.

+

[Coding Computing Coach @CodingComputing]

@PythonPr So, the single item 5 is repeated 3 times.

[5] * 3 gives [5, 5, 5].

That is what gets printed.

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: [5, 5, 5]

Solution: The value of x is [5].

Observe that it is a list with a single item, 5.

Now, what is x * 3?

How do you multiply a list with a number?

The answer is, python repeats the list.

So,
[5] * 3
is the items in the list [5], repeated 3 times.

+

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: 11

Solution:
a is 5 and b is 2.

We have to evaluate
a + b * 3
ie
5 + 2 * 3

multiplication has higher precedence,
so 2 * 3 is worked out first
5 + 2 * 3
simplifies to
5 + 6

which is just
11

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: [3, 5, 8]

Solution: `sorted` is a built-in function.

it takes a list as an argument, and returns a sorted copy of it.

The sorting is in increasing order.

Therefore, sorted([8, 3, 5]) gives [3, 5, 8].

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: True

Solution: {1, 2} and {2, 1} are sets.

In sets, the order of the elements doesn't matter.

A set is like a bag with fruits, shuffled. There is no "first" or "second". The only meaningful question is,
"Is this item in the bag or not?"

{1, 2} has two items: 1, 2

+

[Python Programming @PythonPr]

Python Quiz: What is the Output?

print({1, 2} == {2, 1})

[Coding Computing Coach @CodingComputing]

@PythonPr {2, 1} has exactly the same items as {1, 2}.

They are specified with a different order, but a set doesn't preserve the order of items anyway.

Two sets are considered equal if they contain exactly the same items.

So, {1, 2} == {2, 1} gives True.

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: True

Solution: {1, 2} and {2, 1} are sets.

In sets, the order of the elements doesn't matter.

A set is like a bag with fruits, shuffled. There is no "first" or "second". The only meaningful question is,
"Is this item in the bag or not?"

{1, 2} has two items: 1, 2

+

[Coding Computing Coach @CodingComputing]

@PythonPr Answer: 77

Solution: x is a string, consisting of one character, 7.

What does it mean to multiply a string by a number, like x*2?

In Python, it means repetition of the string.

x*2 repeats the string "7" twice, resulting in the string "77", which is printed as
77