Im new to python and im trying to write a code which determine all the multiples of 5 in a range specified by the user. Im getting the code to go up in units of 5. eg if the range was 6 and 21, it would say that the multiples are 6,11,16,21.
a = int(input("Enter a value of a : "))
b = int(input("Enter a vlue of b : "))
if a%5 ==0:
a = a+5
multiples = []
for value in range(a, b+1,5):
multiples.append(value)
print(multiples)
I'm expected just multiples of 5 to be printed.
If your expected output from the range 6 to 21 is [10, 15, 20], you can first test if the starting point is a multiple of 5 as you did with if a % 5 == 0, and if it is true, we can add 5 repeatedly until we hit the end of range, while appending all the steps into the output list.
However if a % 5 == 0 gives you false, then we need to find the value to add to this starting point so that we can get the first multiple of 5 in this range, i.e.
diff = 5 - a % 5
and add this value to the starting point a, we get the first value:
first = a + diff
Then we can add 5 repeatedly until we hit the end of range.
To put all the above into code:
# get user input for the range a to b
a = int(input("Enter a value of a : "))
b = int(input("Enter a value of b : "))
output_list = []
# determine first value
if a % 5 == 0:
first_val = a
else:
first_val = a + (5 - (a % 5))
# go through the range between the first value and the end, with step=5
for val in range(first_val, b + 1, 5):
# append value to the list
output_list.append(val)
print(output_list)
You could add the following to your if statement:
else: # if it isn't a multiple of 5
a += (5-a%5) # add enough to get to the next multiple of 5
I think you need to find the reminder of input1 and then start looping with that reminder
a = int(input("Enter a value of a : "))
b = int(input("Enter a vlue of b : "))
c=a%5 #reminder
multiples = []
for value in range(a+5-c, b+1,5):
multiples.append(value)
print(multiples)
Related
I'm working on a card number check code, for now I created a function that asks for the card number and checks if it is 8 digits or not (it has to be 8) and then calls another function that will do the math and check if the card is valid. For this function:
Starting from the rightmost digit, form the sum of every other digit. For example, if the card number is 1234 5678, then you form the sum 8 + 6 + 4 + 2 = 20
Double each of the digits that were not included in the preview step and then add all digits of the resulting numbers. For example, the digits that were not included are 7 5 3 1, we double the, 14 10 6 2, and then we sum each digit, 1 + 4 + 1 + 0 + 6 + 2 = 14
Add the sums of the two steps, 20 + 14 = 34, if the last digit is 0 then the card is valid, otherwise it is not valid (which is our case)
My problem is that I don't know how to iterate and get the sum of every other digit or double the other number which were not included in step 2. My thought was to use a while loop but then what?
EDIT: since some answers used lists... we didn't study lists yet, so I should not use it, we are only allowed to use sample stuff, loops, functions, etc.. even sum(map()) we didn't study
That is my code for now (its not much but just thought put it anyway)
def getCard():
CardInput = int(input("Enter your 8 digit credit card number: "))
if len(CardInput) == 8:
CardCheck(CardInput)
else:
print("Invalid Input: Should be exactly 8 digits!")
getCard()
def CardCheck(CardNumber):
Position = 0
Sum = 0
DoubleSum = 0
FinalSum = 0
while CardNumber >= 0:
Position += 1
So, the ugly way of doing is, you can write a for loop and use indexing for access specific elements
for i in range(len(CardInput)):
# it will iterate from 0 to 7
print(CardInput[i]) # here you get ith element
if i % 2 == 1:
print("I am other!") # you can sum your things here into another variable
Or with while:
while position < len(CardInput):
print(CardInput[position])
position += 1
It assumes CardInput is str, so I recommend to not convert it earlier.
However pythonic way would be
sum(map(int, CardInput[1::2])))
CardInput[1::2] returns list of every second element starting from second (0 is first).
map converts every element to in.
sum sums elements.
prompt = "Enter the eight-digit number: "
while True:
number = input(prompt)
if len(number) == 8 and number.isdigit():
break
prompt = "Oops, try again: "
first_digits = number[1::2] # If the user entered '12345678', this will be the substring '2468'
first_sum = sum(map(int, first_digits)) # Take each digit (character), map it to a single-digit integer, and take the sum of all single-digit integers
second_digits = number[0::2] # If the user entered '12345678', this will be the substring '1357'
doubled_ints = [int(char) * 2 for char in second_digits] # Take each digit (character), turn it into an integer, double it, and put it in a list.
second_sum = sum(map(int, "".join(map(str, doubled_ints)))) # Merge all integers in 'doubled_ints' into a single string, take each character, map it to a single digit integer, and take the sum of all integers.
total_sum = first_sum + second_sum
total_sum_last_digit = str(total_sum)[-1]
is_valid_card = (total_sum_last_digit == '0')
if is_valid_card:
print("Your card is valid (total sum: {})".format(total_sum))
else:
print("Your card is NOT valid (total sum: {})".format(total_sum))
def getCard():
CardInput = input("Enter your 8 digit credit card number: ")
if len(CardInput) == 8:
CardCheck(CardInput)
else:
print("Invalid Input: Should be exactly 8 digits!")
getCard()
def CardCheck(CardNumber):
list_CardNumber = [x for x in "25424334"]
Sum = sum(int(x) for x in list_CardNumber[1:8:-2])
DoubleSum = 2*sum(int(x) for x in list_CardNumber[0:8:-2])
FinalSum = Sum + DoubleSum
if str(FinalSum)[-1] == "0":
print("Valid Input")
else:
print("Invalid Input")
To get you started, you should check out enumerate(), it'll simplify things if you're just going to use loops by giving you easy access to both the index and value every loop.
step1 = 0
for i, x in enumerate(number):
if i % 2:
print('index: '+ str(i), 'value: '+ x)
step1 += int(x)
print('step 1: ', step1)
Output:
index: 1 value: 2
index: 3 value: 4
index: 5 value: 6
index: 7 value: 8
step 1: 20
You can use:
# lets say
CardNumber = '12345678'
# as mentioned by kosciej16
# get every other digit starting from the second one
# convert them to integers and sum
part1 = sum(map(int, CardNumber[1::2]))
# get every other digit starting from the first one
# convert them to integers and double them
# join all the digits into a string then sum all the digits
part2 = sum(map(int,''.join(list(map(lambda x: str(int(x)*2), CardNumber[0::2])))))
result = part1 + part2
print(result)
Output:
34
Edit:
Only with loops you can use:
# lets say
CardNumber = '12345678'
total_sum = 0
for idx, digit in enumerate(CardNumber):
if idx % 2 == 1:
total_sum += int(digit)
else:
number = str(int(digit)*2)
for d in number:
total_sum += int(d)
print(total_sum)
output:
34
Since you need to iterate over the digits, it's actually easier IMO if you leave it as a string, rather than converting the input to an int; that way you can just iterate over the digits and convert them to int individuall to do math on them.
Given an 8-digit long string card, it might look like this, broken into steps:
even_sum = sum(int(n) for n in card[1::2])
double_odds = (2 * int(n) for n in card[0::2])
double_odd_sum = sum(int(c) for do in double_odds for c in str(do))
All together with some logic to loop while the input is invalid:
def get_card() -> str:
"""Returns a valid card number, or raises ValueError."""
card = input("Enter your 8 digit credit card number: ")
if len(card) != 8 or not card.isdecimal():
raise ValueError("Invalid input: Should be exactly 8 digits!")
card_check(card)
return card
def card_check(card: str) -> None:
"""Raises ValueError if card checksum fails, otherwise returns None."""
even_sum = sum(int(n) for n in card[1::2])
double_odds = (2 * int(n) for n in card[::2])
double_odd_sum = sum(int(c) for do in double_odds for c in str(do))
if (even_sum + double_odd_sum) % 10:
raise ValueError("Card checksum failed!")
while True:
try:
print(f"{get_card()} is a valid card number!")
except ValueError as e:
print(e)
Help! I'm a Python beginner given the assignment of displaying the Collatz Sequence from a user-inputted integer, and displaying the contents in columns and rows. As you may know, the results could be 10 numbers, 30, or 100. I'm supposed to use '\t'. I've tried many variations, but at best, only get a single column. e.g.
def sequence(number):
if number % 2 == 0:
return number // 2
else:
result = number * 3 + 1
return result
n = int(input('Enter any positive integer to see Collatz Sequence:\n'))
while sequence != 1:
n = sequence(int(n))
print('%s\t' % n)
if n == 1:
print('\nThank you! The number 1 is the end of the Collatz Sequence')
break
Which yields a single vertical column, rather than the results being displayed horizontally. Ideally, I'd like to display 10 results left to right, and then go to another line. Thanks for any ideas!
Something like this maybe:
def get_collatz(n):
return [n // 2, n * 3 + 1][n % 2]
while True:
user_input = input("Enter a positive integer: ")
try:
n = int(user_input)
assert n > 1
except (ValueError, AssertionError):
continue
else:
break
sequence = [n]
while True:
last_item = sequence[-1]
if last_item == 1:
break
sequence.append(get_collatz(last_item))
print(*sequence, sep="\t")
Output:
Enter a positive integer: 12
12 6 3 10 5 16 8 4 2 1
>>>
EDIT Trying to keep it similar to your code:
I would change your sequence function to something like this:
def get_collatz(n):
if n % 2 == 0:
return n // 2
return n * 3 + 1
I called it get_collatz because I think that is more descriptive than sequence, it's still not a great name though - if you wanted to be super explicit maybe get_collatz_at_n or something.
Notice, I took the else branch out entirely, since it's not required. If n % 2 == 0, then we return from the function, so either you return in the body of the if or you return one line below - no else necessary.
For the rest, maybe:
last_number = int(input("Enter a positive integer: "))
while last_number != 1:
print(last_number, end="\t")
last_number = get_collatz(last_number)
In Python, print has an optional keyword parameter named end, which by default is \n. It signifies which character should be printed at the very end of a print-statement. By simply changing it to \t, you can print all elements of the sequence on one line, separated by tabs (since each number in the sequence invokes a separate print-statement).
With this approach, however, you'll have to make sure to print the trailing 1 after the while loop has ended, since the loop will terminate as soon as last_number becomes 1, which means the loop won't have a chance to print it.
Another way of printing the sequence (with separating tabs), would be to store the sequence in a list, and then use str.join to create a string out of the list, where each element is separated by some string or character. Of course this requires that all elements in the list are strings to begin with - in this case I'm using map to convert the integers to strings:
result = "\t".join(map(str, [12, 6, 3, 10, 5, 16, 8, 4, 2, 1]))
print(result)
Output:
12 6 3 10 5 16 8 4 2 1
>>>
1.7 LAB: Adjust values in a list by normalising
When analysing data sets, such as data for human heights or for human weights, a common step is to adjust the data. This can be done by normalising to values between 0 and 1, or throwing away outliers.
Write a program that first gets a list of integers from input. The input begins with an integer indicating the number of integers that follow. Then, adjust each integer in the list by subtracting the smallest value from all the integers.
Ex: If the input is:
5
30
50
10
70
65
the output is:
20
40
0
60
55
The 5 indicates that there are five integers in the list, namely 30, 50, 10, 70, and 65. The smallest value in the list is 10, so the program subtracts 10 from all integers in the list.
Anyone can solve this question in python?
This is my code.
arr1 = []
input = int()
for i in range(0,input):
e = int(intput())
arr1.append(e)
k = min(arr1)
for i in range(0,val):
arr1[i] = arr1[i] - k
for i in range(0,val):
print(arr1[i])
Here is the error.
Traceback (most recent call last):
File "main.py", line 8, in <module>
arr1.append(e)
NameError: name 'e' is not defined
You could use list comprehension:
input = [5,30,50,10,70,65]
input = input[1:]
output = [i - min(input) for i in input]
print(output)
[20, 40, 0, 60, 55]
This is the way I solved it
list = []
values = int(input())
for n in range(values):
number = float(input())
list.append(number)
largest = max(list)
for number in list:
number = number / largest
print(f'{number:.2f}')
def get_minimum_int(nums):
low = min(nums)
return low
if __name__ == '__main__':
num = int(input())
nums = []
while num != -1:
nums.append(num)
num = int(input())
l = get_minimum_int(nums)
for n in nums:
print(n - l)
idk if your question ever got answered but I also had the same type of task.
Mine was:
"For this program, adjust the values by dividing all values by the largest value. The input begins with an integer indicating the number of floating-point values that follow.
Output each floating-point value with two digits after the decimal point, which can be achieved as follows:
print('{:.2f}'.format(your_value))
Ex: If the input is:
5
30.0
50.0
10.0
100.0
65.0
the output is:
0.30
0.50
0.10
1.00
0.65
The 5 indicates that there are five floating-point values in the list, namely 30.0, 50.0, 10.0, 100.0, and 65.0. 100.0 is the largest value in the list, so each value is divided by 100.0."
So this is how I solved mine:
x = int(input())
dislist = []
i = 1
while i <= x:
y = float(input())
dislist.append(y)
i += 1
q = max(dislist)
for item in dislist:
item = item / q
print('{:.2f}'.format(item))
Tell me what you think :)
A few problems I can see with your code.
input = int()`
input in the name of a function that gets an input string from the user. int() simply returns 0. You are assigning the value 0 to a variable named input, making the input function no longer accessible.
for i in range(0,input):
e = int(intput())
Because input is 0, this is an empty range. The loop never runs. Which is good because it would have no idea what intput is.
Because the loop never runs, e is never defined, which is why you get the error you do.
Another style note: arr1 is a list so using a name that suggests it's an array is misleading.
You likely wanted something like the following tweaked version of your code.
n = int(input())
vals = []
for _ in range(0, n):
e = int(input())
vals.append(e)
k = min(vals)
for i in range(0, n):
arr1[i] = -= k
for i in range(0, n):
print(arr1[i])
Gathering the input numbers could be simplified using a list comprehension.
vals = [int(input()) for _ in range(0, n)]
This may be helpful for your lab:
user_int = []
while True:
user_input = int(input())
user_int.append(int(user_input))
if len(user_int) > (int(user_int[0])):
break
user_int.pop(0)
vals = min(user_int)
for user_vals in user_int:
my_vals = user_vals - vals
print(my_vals)
So, maybe this question will sound very beginnerish, but I just don't know how I should begin with this example:
So the example is:
I have a list for example 13 items long (1,2,3,4...13)
There's a given number, let's say 6
The program needs to show me in a list, in what order are the numbers going to fall out. If the second number is 6, it means every time the sixth item is the next whcih is going to fall out. But my problem is that how could I tell python that if the index number goes up too high, it should start counting again from the beggining?
This is what I made myself so far
x = int(input("Number of items (numbers): "))
y = int(input("Fall-out number: "))
#n = 1
#id = 0
numbers = [n for n in range(x+1)]
fallsout = []
numbers.remove(30)
for i in numbers:
if i % y == 0:
fallsout.append(i)
print (numbers)
print (fallsout)
Here's an example what should be in the input and output:
Input:
x = 13
y = 6
Output: 6 12 5 13 8 3 1 11 2 7 4 10 9
Okay, looks like you want to copy every 6th element from numbers into fallout and then remove the element from numbers, and continue on in a cyclic fashion until numbers is empty.
import copy
x = int(input("Number of items (numbers): "))
y = int(input("Fall-out number: "))
# list should start from 1 as by the example
numbers = [n for n in range(1,x+1)]
# deep copy to preserve original list
numbers_copy = copy.deepcopy(numbers)
fallsout = []
count = y
while len(numbers_copy)!=0:
fallsout.append(numbers_copy[count-1])
# remove element
del numbers_copy[count-1]
# handle starting edge
if count == 0:
count = 1
# handle last edge
if numbers_copy != []:
count = (count+y-1)%len(numbers_copy)
print numbers
print fallsout
Output is
Number of items (numbers): 13
Fall-out number: 6
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
[6, 12, 5, 13, 8, 3, 1, 11, 2, 7, 4, 10, 9]
Explanation:
Suppose I have a array numbers = [1,2,3,4,5,6] of length=6, and I am using an counter "count" to iterate through the list. So that,
numbers[count] = 2 (when count=1)
Then to look at the next element, I would use numbers[count+1].
To jump back to the starting of the list, we use modulus operation,
count = (count+number_of_steps)%len(numbers)
eg, at index=4 and to jump 3 steps, next index would be (4+3)%6 = 1
Now we have to copy every yth element from the list,so we use,
fallsout.append(numbers_copy[count-1]) # count-1 as we are counting from 0
Then we remove that number from the list,
del numbers_copy[count-1]
Then we jump forward count by y steps by modulus as discussed above,
count = (count+y-1)%len(numbers_copy) # again -1 as we count from 0
The length of numbers needs to be calculated again as the list could change due to deleting of elements.
I haven't found anything even relevant to my question, so i may be asking it wrong.
I am working on an exercise where I am given sequential values starting at 1 and going to n, but not in order. I must find a missing value from the list.
My method is to add the full 1 => n value in a for loop but I can't figure out how to add n - 1 non-sequential values each as its own line of input in order to subtract it from the full value to get the missing one.
I have been searching modifications to for loops or just how to add n inputs of non-sequential numbers. If I am simply asking the wrong question, I am happy to do my own research if someone could point me in the right direction.
total = 0
for i in range (1 , (int(input())) + 1):
total += i
print(total)
for s in **?????(int(input()))**:
total -= s
print(total)
sample input:
5
3
2
5
1
expected output: 4
To fill in the approach you're using in your example code:
total = 0
n = int(input("How long is the sequence? "))
for i in range(1, n+1):
total += i
for i in range(1, n):
total -= int(input("Enter value {}: ".format(i)))
print("Missing value is: " + str(total))
That first for loop is unnecessary though. First of all, your loop is equivalent to the sum function:
total = sum(range(1,n+1))
But you can do away with any iteration altogether by using the formula:
total = int(n*(n+1)/2) # division causes float output so you have to convert back to an int
I don't know if you are supposed to create the initial data (with the missing item), so I added some lines to generate this sequence:
import random
n = 12 # or n = int(input('Enter n: ')) to get user input
# create a shuffled numeric sequence with one missing value
data = list(range(1,n+1))
data.remove(random.randrange(1,n+1))
random.shuffle(data)
print(data)
# create the corresponding reference sequence (without missing value)
data2 = list(range(1,n+1))
# find missing data with your algorithm
print("Missing value =", sum(data2)-sum(data))
Here is the output:
[12, 4, 11, 5, 2, 7, 1, 6, 8, 9, 10]
Missing value = 3