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Let s be a string containg several characters some of which may be digits. Write a function that returns the sum of all digits in that string.

def sum_digits_in_string(s): """Return sum of all digits in a string. :param s: string containing the digits and other characters :return: numeric value, sum of all digits Examples: >>> sum_digits_in_string('1') 1 >>> sum_digits_in_string('hi 1 hello 2') 3 >>> sum_digits_in_string('Values: 1.26, 2.3, 1.76') 28 """

Let s be a string containing decimal numbers separated by commas, e.g. s = '1.26,2.3,1.76'. Write a function that returns the sum of all decimal numbers in that string.

def sum_decimals_in_string(s): """Return sum of decimal numbers in a string. :param s: string containing the decimal numbers separated by ',' :return: float, sum of all decimals Examples: >>> sum_decimals_in_string('1.2') 1.2 >>> sum_decimals_in_string('1.2,3.4') 4.6 >>> sum_decimals_in_string('1,2,0.000001') 3.000001 """

Using nested loops, write function `print_left_triangle(n_rows, char)`

which prints the triangle depicted below. E.g. when you call that function like this:

>>> print_left_triangle(n_rows=5, char='T') T TT TTT TTTT TTTTT

Again, using nested loops, write function `print_right_triangle(n_rows, char)`

which prints the triangle depicted below. E.g. when you call that function like this:

>>> print_right_triangle(n_rows=5, char='T') T TT TTT TTTT TTTTT

Write a function `combine_elements(el1, el2)`

which takes 2 iterables (e.g. lists) of chemical elements, and returns a list of all possible compounds that can arise by combining an element from the first list with an element from the second list.

def combine_elements(el1, el2): """Return a list of possible compounds each containg a single element from both the first and second list. :param el1: list of strings, symbols of chemical elements for the first place of compound :param el2: list of strings, symbols of chemical elements for the second place of compound :return: list of strings, possible chemical compounds Example: >>> metals = 'Li Na K'.split() >>> halogens = 'F Cl Br'.split() >>> print(combine_elements(metals, halogens)) ['LiF', 'LiCl', 'LiBr', 'NaF', 'NaCl', 'NaBr', 'KF', 'KCl', 'KBr'] """

* Somewhat more complex task for more advanced students.*

Your small company produces wooden chairs and tables. Profit from a single chair is `profit_per_chair`

, profit from a single table is `profit_per_table`

. To build a single chair, you need to invest `wood_per_chair`

units of wood and `manhours_per_chair`

manhours of labour, to build a single table you need to invest `wood_per_table`

units of wood and `manhours_per_table`

manhours of labour. How many chairs and tables (`n_chairs`

, `n_tables`

) should you produce per day to maximize your profit, if you can invest `available_manhours`

manhours a day and `available_wood`

units of wood a day, and if you want the numbers of chairs and tables to be integers?

Write a function that returns the optimal values given all the parameter values as arguments.

def compute_optimal_production(profit_per_chair, profit_per_table, wood_per_chair, wood_per_table, manhours_per_chair, manhours_per_table, available_wood, available_manhours): """Return numbers of chairs and tables to be produced per day to maximize profit. :param profit_per_chair: Company profit for a single chair produced. :param profit_per_chair: Company profit for a single table produced. :param wood_per_chair: Amount of wood required to build a single chair. :param wood_per_table: Amount of wood required to build a single table. :param manhours_per_chair: Amount of work required to build a single chair. :param manhours_per_table: Amount of work required to build a single chair. :param available_wood: Total amount of wood available for production each day. :param available_manhours: Total amount of work available each day. :return: (n_chairs, n_tables) tuple containing the optimal number of chairs and tables produced each day. Example: >>> profit_per_chair, profit_per_table = 20, 30 >>> wood_per_chair, manhours_per_chair = 1, 3 >>> wood_per_table, manhours_per_table = 6, 1 >>> available_wood, available_manhours = 288, 99 >>> print(compute_optimal_production( profit_per_chair, profit_per_table, wood_per_chair, wood_per_table, manhours_per_chair, manhours_per_table, available_wood, available_manhours)) (18, 45) """

Suggestion: Proceed in smaller steps.

- Create helper function to compute the total profit from x chairs and y tables.
- Create a helper function telling you, whether when producing x chairs and y tables, the available amount of wood is or is not exceeded.
- Create a helper function telling you, whether when producing x chairs and y tables, the available manhours are or are not exceeded.
- Compute the maximal number of chairs and tables that can be produced per day, if you decided to produce only chairs/only tables.
- Then combine it all to complete function
`compute_optimal_production()`

. Perform exhaustive search among all feasible pairs of values for`n_chairs`

and`n_tables`

.

- Finish all the above tasks.
- Read chapter 12 of [Wenthworth].

courses/be5b33prg/labs/week_05.txt · Last modified: 2018/10/30 13:33 by iscenahm