CODEWITHSUNDEEP
pythonpython-3.xfunction
user10427550
user10427550

Reputation:

How to create a function to find numbers divisible by 7 but not by 5

Im trying to write a function named find_numbers that will find all numbers divisible by 7 and not by 5.

My issue is the actual function this is what I have so far:

def find_numbers(lower_bound, upper_bound):
    for i in range(lower_bound,upper_bound):
        if (i % 7 == 0 and i % 5 !=0):
            print(i)

return ()

do i have the correct parameters? what exactly am i returning? I feel that i'm close to the correct solution, but I really am stuck :( It's printing out what I want, sort of, but not correctly. Any help is really appreciated!! Thank you all. 

lower_bound = int( input("Lower bound to search for numbers: ") )
upper_bound = int( input("Upper bound to search for numbers: ") )

found_numbers = find_numbers(lower_bound, upper_bound)

print("The numbers that are divisible by 7 but not by 5 
are:\n{}".format(found_numbers))

Upvotes: 0

Views: 3930

Answers (4)

juanmf
juanmf

Reputation: 2004

You can think of it like pattern, offset, instead of lower and upper bounds.

7 * 5 = 35 => you’ll have a harmonic pattern of length 35, where 7, 14, 21, 28 are your numbers of interest, 35 is the one you skip. Add n * 35 as offset and you have the infinity at the reach of your hands 😏

Sorry to use java. On the go with my cell it’s what I have on the top of my mind easier. 

List<Integer> pattern = Arrays.asList(7, 14, 21, 28);
Stream.iterate(0, offset -> offset + 1)
      .forEach(offset -> pattern.stream()
                                .forEach(p -> print(35 * offset + p))
      );

Upvotes: 0

Sreeram TP
Sreeram TP

Reputation: 11927

You can use a simple list comprehension for this purpose.

result = [x for x in range(lower_bound, upper_bound) if x % 7 == 0 and x % 5 != 0]

You can wrap it in a function if you want to make more elegant and re-usable like this.

def find_numbers(lower_bound, upper_bound):
    return [x for x in range(lower_bound, upper_bound) if x % 7 == 0 and x % 5 != 0]


lower_bound = int( input("Lower bound to search for numbers: ") )
upper_bound = int( input("Upper bound to search for numbers: ") )

found_numbers = find_numbers(lower_bound, upper_bound)

print("The numbers that are divisible by 7 but not by 5 are:\n{}".format(found_numbers))

It can be seen that this method of list comprehension will run a little faster than conventional looping solution.

Upvotes: 3

Osman Mamun
Osman Mamun

Reputation: 2882

There are several things wrong in the logic:

  1. It will only print the last value found
  2. the return statement is not right
  3. What if there is not number in that range

I'd modify it like this:

In [1]: def find_numbers(L, U):
...:     r = []
...:     for i in range(L, U):
...:         if i % 7 == 0 and i % 5 != 0:
...:             r.append(i)
...:     if not r:
...:         return None
...:     else:
...:         return r
...:

Upvotes: 1

BAKE ZQ
BAKE ZQ

Reputation: 807

def find_numbers(lower_bound, upper_bound):
    results=[]
    for i in range(lower_bound,upper_bound):
      if (i % 7 == 0 and i % 5 !=0):
          results.append(i)
    return results

lower_bound = int( input("Lower bound to search for numbers: ") )
upper_bound = int( input("Upper bound to search for numbers: ") )

found_numbers = find_numbers(lower_bound, upper_bound)

print("The numbers that are divisible by 7 but not by 5 
are:\n{}".format(found_numbers))

Upvotes: 5

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