Demo Lecture Part 2

Question 1

what is a function? (4)

Answer 1

1 A process for executing a task
2 It can accept input and return an output
3 Useful for executing similar procedures over and over
4 store a piece of code that can be reused at different places in our program.

Question 2

what is the return keyword? (3)

Answer 2

1 The return statement causes your function to exit and hand back a value to its caller.
2 If you don’t supply an explicit return statement with an explicit return value, then Python will supply an implicit return statement using None as a return value.
3 You can return more than one piece of information and it ill be represented in the form of a tuple.

Question 3

what is the syntax for returning variables a, b, and c

Answer 3

return (a, b, c)

will print a tuple in the console

Question 4

how do you write an empty function?

Answer 4

by using the pass statement

Question 5

what is the difference between parameter and argument?

Answer 5

Parameter is variable in the declaration of function. Argument is the actual value of this variable that gets passed to function.

Question 6

what are default parameters? (3)

Answer 6

1 default values declared when the function is defined. eg def a(m=2)

2 default parameters must be defined last in the list of parameters.

3 if you don’t add anything in their position when you call the function, the default parameter will be used, so remember what it is!

Question 7

what is the ‘end’ parameter? (2)

Answer 7

1 parameter of the last character of the print statement.
2 by default it’s \n so the \n will be completely replaced unless you add it.

Question 8

what are the 3 common mistakes when using a return statement?

Answer 8

1. returning too early
2. return statement inside the loop
3. unnecessary else condition

Question 9

what are keyword arguments? (5)

Answer 9

1 also known as kwargs

2 allows you to take in more arguments than the number of formal arguments that you previously defined.

3 When passed to the functions, identified by the name of the parameter.

4 So the order of the arguments does not matter anymore

5 We can alter the order that the things are passed

Question 10

how do you format a string using %s?

Answer 10

name=’hayley’

print(“Hey, %s!” % name)

Question 11

how do you format a string using %d?

Answer 11

age=40
print(“I am %d years old.’ %age)

Question 12

how do you format for multiple strings? (2)

Answer 12

1 The strings are replaced in the order of their position in the brackets, wherever there is an %s sign

2 However, the number of occurrences of this operator must be equal to the number of strings to replace with after the % sign. Otherwise, an error o

Question 13

what do you need to remember when using %s in a dictionary?

Answer 13

The strings are printed in whatever order they are appended using the dictionary key in output.

Question 14

what is *args? (2)

Answer 14

1 used to pass a non-keyworded, variable-length argument list.
2 so you can take in more arguments than the number of formal arguments that you previously defined.

Question 15

explain %d operator (3)

Answer 15

1 The %d operator is used as a placeholder to specify integer values, decimals, or numbers.

2 It allows us to print numbers within strings or other values.

3 Floating-point numbers are converted automatically to decimal values.

Question 16

how do you access the documentation of a function? (2)

Answer 16

1 print(functionname.methodname__doc__)

or just

2 print(functionname.__doc__) without the methodname

Question 17

break vs return vs pass

Answer 17

Break is used for LOOP, exits the loop ONLY.
return is used for functions, exits the WHOLE FUNCTION and throws a value back to the caller

pass is to avoid throwing error but no code written, does nothing.

Question 18

how do you reverse a list?

Answer 18

list[::-1]

Question 19

what is the count method? what is its syntax?

Answer 19

• returns the number of elements with the specified value.
• syntax: listname.count(value)