Python Basics IV Functions, Map, and Lambda

Question 1

How do you create a function in Python

Answer 1

use def, a colon, then indent.

Question 2

What is map used for?

Answer 2

A code convenience, it makes it easy to apply a function to all the elements of a list.

Question 3

What is lamda for?

Answer 3

To streamline code, you basically need function, but it’s a one shot deal, so you woud like to avoid the overhead required to construct a proper function.

Question 4

Can you write a function on a single line. (So there would be no indenting)?

Answer 4

Yes

Question 5

Map applies a function (or lambda expression) to every element in a list. FILTER works similarly, but applies a filter to every element in a sequence. Using filter, write an expression that would only return the even number from a list of numbers.?

Answer 5

Question 6

What does the split method do?

Answer 6

You can apply it to a string, it will create a list where each element between the blanks shows.
Suppose, for example we wanted to extract the tag in a tweet. It would be done as shown.

Question 7

What are the 2 important dictionary methods?

Answer 7

.keys and .values
A dictionary is a collection of key/value pairs.

Question 8

Does a Python list have a Push and Pop method?

Answer 8

No, it has Append and Pop methods. Those methods have an optional integer argument. The default value is 0.

Question 9

What method returns a boolean to determine if an item is in a list.

Answer 9

The “in” method

Question 10

What is tuple unpacking

Answer 10

It is a shortcut method for extracting items from tuples when you have a list of tuples.