1. write a multiply_by_10() function

create a function named ‘multiply_by_10’ that

• receives one parameter x
• returns x multiplied by 10

2. triangles

we’re going to write function to print triangles that look like this:

   *
   **
   ***
   ****

create a function called ‘print_asterics’ that

• receives one parameter called n
• prints to screen one line with n asterics

>>> print_asterics(4)
****
>>> print_asterics(8)
********

use this function and a for loop to print a triangle having 10 lines

3. write print_char() function

create a new function called print_char that works similarly to print_asterics,

• except it receives the character to print as an additional parameter called ‘c’
• the param c should have a default value of ‘*’

>>> print_char(4)
****
>>> print_char(8, '@')
@@@@@@@@ 

use this function to create this triangle with a loop

@
@@
@@@
@@@@

4. function print_trian()

create a function print_trian to print triangles like in #3 it should receive two parameters:

• n determines how many lines the triangle would have
• c determines the character to use, with ‘*’ as default

>>> print_trian(5, '$')
$
$$
$$$
$$$$
$$$$$

• hint: this function should use print_char internally

4.b write get_trian() function with return value

create a new function called get_trian, that is very similar to print_trian from #4, but instead of printing the triangle it returns the triangle as a string

>>> x = get_trian(5, '$')
>>> print(x)
$
$$
$$$
$$$$
$$$$$

my_abs(x) function

in this exercise we’re going to implement a funtion that calculates the absolute value (ערך מוחלט) of a parameter x and we’re going to do it in 3 styles.

   x = my_abs(-10)
   print(x) # prints 10

   y = my_abs(12)
   print(y) # prints 12

1. write a function called my_abs(x) that calculates the absolute value (ערך מוחלט) of a parameter x

### useful: this tests your function
assert my_abs(0) == 0
assert my_abs(-10) == 10
assert my_abs(15) == 15

1. write a function called my_abs2(x) that does the same calculation as my_abs(x)
   BUT use the single line if variant: exprssion1 if condition else expression2

1. implement absolute value function using lambda syntax, put the result in a variable called my_abs3

calculate VAT “מס ערך מוסף”

a) write a function called calc_vat that takes a price and the VAT and calculates how much the price is after VAT

for instance:

>>> calc_vat(100, 17)
117

b) make the vat a default parameter with value 17

>>> calc_vat(100)
117

>>> calc_vat(100, 15)
115

zip-ing two lists together

1. create a list of fruits, put it in a variable called fruits.

   example: ['apple', 'guava', 'pineapple', 'pear', 'peach']

2. create a list of prices for these fruits. it should have the same length as your list of fruits. put it in a variable called prices.

   example: [10, 12, 20, 5, 8]

3. use the zip function (look it up on google) to create a list of fruit/price pairs.

   it could look like this: [('apple', 10), ('guava', 12), ('pineapple', 20), ('pear', 5), ('peach', 8)] ```

make_matrix() function

write a function called make_matrix(nrows=10, ncols=10) that returns a multiplication matrix (לוח כפל) with nrows rows and ncols rows.

the function will return a list of lists that have the following property:

make_matrix()[i][j] == i*j

for example:

>>> from pprint import pprint
>>> x = make_matrix(5, 5)
>>> pprint(x)
[[0, 0, 0, 0, 0],
 [0, 1, 2, 3, 4],
 [0, 2, 4, 6, 8],
 [0, 3, 6, 9, 12],
 [0, 4, 8, 12, 16]]

write maxitem() function

create a function called maxitem that finds and returns the maximum item in a list

>>> maxitem([1,2,3,4,3,1])
4

sort_lists() - difficult

create a function called sort_lists that can sort a list of lists. [find hints on how to do it below.]

it will work in the following way:

• we will sort lists according to which one has the maxmium item (like in #5)
• example:

  >>> sort_lists([
   [1,2,3],
   [2,3,4],
   [1,1,1],
   [2]
   ])
  [
  [1,1,1],
  [2],
  [1,2,3],
  [2,3,4
  ]
  

• hint: use the function maxitem from #5 and the existing function sorted

make_add_x - difficult

create a function called make_add_x() that receives one parameter x and returns an inner function … this inner function will receive one parameter y and return x+y

>>> add7 = make_add_x(7)
>>> add7(3)
10
>>> add7(5)
12
>>> add10 = make_add_x(10)
>>> add10(100)
110

myprint() - challenging

create a function called myprint that has similar properties to the built-in print() function:

• it is variadic: it can support 0,1,2,3 or more parameters (unlimited number)
• it supports the file, sep and end arguments

it differrs from print by prefering the character @

>>> myprint(1, 2, 3)
1 @ 2 @ 3 @
>>> myprint( [1, 2, 3], [4, 5, 6] )
[1, 2, 3] @ [4, 5, 6] @

>>> myprint(1, 2, 3, file=sys.stdout, sep=' ', end='\n')
1 2 3

make_debuggable() - very difficult

create a function called make_debuggable(func) that:

• receives one paramter called func
• returns a new function that does the same thing as func,

and can accept any argument that func accepts.

• but in addition the returned function also helps debugging by printing out the parameters it received, and the return value it is about to return

hints:

• use a nested function that accepts variadic positional and keyword arguments