Python: Data Aggregation (Strings)
Like with number aggregation, string aggregation involves not knowing what the strings contain and how big they are.
Imagine a function that knows how to multiply a string; it repeats it a specified number of times:
repeat('hexlet', 3) # 'hexlethexlethexlet'
The principle of how this function works is that in the loop, the string is “incremented” a specified number of times:
def repeat(text, times):
# The neutral element for strings is an empty string
result = ''
i = 1
while i <= times:
# Each time we add the string to the result
result = result + text
i = i + 1
return result
Let's break down the code's execution into steps:
# To call repeat('hexlet', 3)
result = ''
result = result + 'hexlet' # hexlet
result = result + 'hexlet' # hexlethexlet
result = result + 'hexlet' # hexlethexlethexlet
Instructions
Implement a function called join_numbers_from_range() that combines all the numbers from a range into a string:
join_numbers_from_range(1, 1) # '1'
join_numbers_from_range(2, 3) # '23'
join_numbers_from_range(5, 10) # '5678910'
The exercise doesn't pass checking. What to do? 😶
If you've reached a deadlock it's time to ask your question in the «Discussions». How ask a question correctly:
- Be sure to attach the test output, without it it's almost impossible to figure out what went wrong, even if you show your code. It's complicated for developers to execute code in their heads, but having a mistake before their eyes most probably will be helpful.
In my environment the code works, but not here 🤨
Tests are designed so that they test the solution in different ways and against different data. Often the solution works with one kind of input data but doesn't work with others. Check the «Tests» tab to figure this out, you can find hints at the error output.
My code is different from the teacher's one 🤔
It's fine. 🙆 One task in programming can be solved in many different ways. If your code passed all tests, it complies with the task conditions.
In some rare cases, the solution may be adjusted to the tests, but this can be seen immediately.
I've read the lessons but nothing is clear 🙄
It's hard to make educational materials that will suit everyone. We do our best but there is always something to improve. If you see a material that is not clear to you, describe the problem in “Discussions”. It will be great if you'll write unclear points in the question form. Usually, we need a few days for corrections.
By the way, you can participate in courses improvement. There is a link below to the lessons course code which you can edit right in your browser.
languages.lessons.show.chat.disabled
Your exercise will be checked with these tests:
1import index
2
3
4def test1():
5 assert index.join_numbers_from_range(2, 2) == '2'
6 assert index.join_numbers_from_range(1, 5) == '12345'
7 assert index.join_numbers_from_range(10, 12) == '101112'
8Teacher's solution will be available in:
