Python

Question 1

What will happen if you try to print a variable that was not defined?

Answer 1

As the variable was not defined, you will get an error message like this one:
NameError: name ‘z’ is not defined

Question 2

What does those operators mean?
x += 2

x -= 2

Answer 2

Equivalent: x = x + 2

Equivalent: x = x - 2

Question 3

What type of data you get when you divide a integer by another integer?

Answer 3

A float

Question 4

What happens when you convert a Float to an Int

Answer 4

The decimal part of the number is cut off

print(int(32.7))

Question 5

If you add 0.1 together why do you get a bigger number than the sum of each number?
For instance?
INPUT:
print(0.1 + 0.1 + 0.1)

OUTPUT:
3.000000000000004

Answer 5

Because a float can represent an enormous range of numbers. In order to fit it in a computer memory, a float, actually, is an aproximation of the number it represents in python.

Question 6

What is a string?

Answer 6

String is a immutable ordered sequence of characters (E.G. letters, numbers, spaces and symbols)

Question 7

Which function in python would you use to find out the number of characters of a string?

Answer 7

len()

Question 8

Why is it important to define what type of data you are going to use for different purposes?

Answer 8

Because for each data type there is different built in functions that work with them.

Question 9

What are methods in Python?

Answer 9

A method in Python behaves similarly to a function. Methods actually are functions that are called using dot notation.

Question 10

In the example first_name.islower() is there an argument along with the islower() method?

Answer 10

Yes, usually teh argument goes inside the parenthesis, but in this case, the argument is “disguised”as “first_name”.

Question 11

What does the following error mean? “SyntaxError: unexpected EOF while parsing”

Answer 11

This message is often produced when you have accidentally left out something, like a parenthesis. The message is saying it has unexpectedly reached the end of file (“EOF”) and it still didn’t find that right parenthesis. This can easily happen with code syntax involving pairs, like beginning and ending quotes also.

Question 12

In Python there are containers of data, which contains other data types and even other containers.

What is consists the container of data List?

Answer 12

List is a data type for mutable ordered sequences of elements.

Question 13

You can pull more than one value of a list using slicing. Although, you must know that the upper and lower index informed behave differently. How?

Answer 13

The lower index is inclusive and the upper index is exclusive.

Question 14

Lists and strings both support indexing, slicing and IN operator.

So, whats the difference between them?

Answer 14

Strings are sequences of letters, while list elements can be any type of object.

One more sutil difference, is that lists can be modified, but strings can’t.

Question 15

How to functions max() works differently with lists of words and numbers?

Answer 15

When working with a list of numbers, max() will bring the largest number in the list.

When working with list of words, max() will bring the word that starts with the biggest letter considering its index in the alphabet

Question 16

When using the method join() in a list of strings, how you separate each element with a line break(enter)?

Answer 16

Using “\n”

Question 17

What is a tuple?

Answer 17

A data type for immmutable ordered sequence of elements. Used to store related pieces of informations like latitude and longitude.

Question 18

What consists tuple unpacking?

Answer 18

You can use tuple unpacking to assign the information from a tuple into multiple variables without having to access them one by one and make multiple assignment statemente:

Instead of this:

dimensions = 52, 40, 100
length, width, height = dimensions
print(“The dimensions are {} x {} x {}”.format(length, width, height))

You can use this:

length, width, height = 52, 40, 100
print(“The dimensions are {} x {} x {}”.format(length, width, height))

Tuples do not require parenthesis.

Question 19

Knowing that a set is a data type for mutable unordered collections of unique elements, how would you use a set structure to get the unique values of a list with repeated values?

Answer 19

numbers = [1, 2, 6, 3, 1, 1, 6]
unique_nums = set(numbers)
print(unique_nums)

Question 20

What is an Iterable?

Answer 20

An object that can return one of its elements at a time.