Okay so I am trying to create an empty list, then add integers to the list to then pick out the highest,lowest and 5 middle numbers( in descending order using a slice) and put them on display... seems simple enough....
def main():
nums = []
for i in range(20,80,9):
nums.append(i)
print(*nums,sep=' ')
print('The highest number is',max(nums))
print('The lowest number is',min(nums))
print('The middle 5 sorted high to low:')
nums.sort()
nums.reverse()
print (*nums[1:6])
main()
Okay so i edited it using your suggestions and the program works fine..... I just cant wrap my head around that damned while loop.... Can anyone see how I could integrate that?
while nums.append(i):. list.append returns None, and None does not evaluate to true. So your print statements will never be executed.
nums.reverse[2:6] reverse is a method and reverses the list in place. It does not return anything. So this part will throw a TypeError. You want to instead call nums.reverse()
The reverse method does not sort. You need nums.sort()
nums[2:6] will get you the elements from index 2 to 6 (exclusive). So this will only get you 4 elements. Additionally, your list has 9 elements (7 if you exclude the min and max). The middle 5 elements would not be between index 2 and 6.
Python has a help() function, use it if you need to know what functions/methods return.
You could refactor your code to use a while loop like so.
def main():
nums = []
i = 20
while i < 80:
nums.append(i)
print(*nums,sep=' ')
i += 9
print('The highest number is',max(nums))
print('The lowest number is',min(nums))
print('The middle 5 sorted high to low:')
# removed on the basis that they are already sorted
#nums.sort()
nums.reverse()
print (*nums[1:6])
main()
It's just a lot nicer using range as you don't need to the i variable outside the scope of the loop.
This is one way to do it:
nums = []
for i in range(20,80,7):
nums.append(i)
mx = max(nums)
mn = min(nums)
nums.remove(mx)
nums.remove(mn)
mx2 = max(nums)
mn2 = min(nums)
nums.remove(mx2)
nums.remove(mn2)
nums.sort()
nums.reverse()
print nums
The output is the 5 middle numbers in descending order:
[62, 55, 48, 41, 34]
and the better, shorter way to do it is this:
def main():
nums = []
for i in range(20,80,7):
nums.append(i)
mx = max(nums)
mn = min(nums)
print "The highest number is %s " % mx
print "The lowest number is %s " % mn
while len(nums) != 5:
nums.remove(max(nums))
nums.remove(min(nums))
nums.sort()
nums.reverse()
print "The middle 5 sorted high to low is %s:" % nums
main()
The output is:
The highest number is 76
The lowest number is 20
The middle 5 sorted high to low is [62, 55, 48, 41, 34]
Related
list = [27 , 39 , 56, 73, 3, 43, 15, 98, 21 , 84]
found = False
searchFailed = False
first = 0
last = len(list) - 1
searchValue = int(input("Which number are you looking for? "))
while not found and not searchFailed:
mid = (first + last) // 2
if list[mid] == searchValue:
found = True
else:
if first >= last :
searchFailed = True
else:
if list[mid] > searchValue:
last = mid - 1
else:
last = mid + 1
if found:
print("Your number was found at location", mid)
else:
print("The number does not exist within the list")
The code runs properly when I execute it while searching for 27 (the first number), but any other number just results in an infinite loop.
I believe the loop runs smoothly on the first iteration since if I change the value of first to 1, the code correctly finds the position of 39 but repeats the infinite loop error with all the other numbers after that (while 27 "does not exist within the loop" which makes sense). So I suppose the value of mid is not getting updated properly.
Several points to cover here. First, a binary search needs sorted data in order to work. As your list is not sorted, weirdness and hilarity may ensue :-)
Consider, for example, the unsorted [27 , 39 , 56, 73, 3, 43, 15, 98, 21] when you're looking for 39.
The first midpoint is at value 3 so a binary search will discard the left half entirely (including the 3) since it expects 39to be to the right of that3. Hence it will never find 39`, despite the fact it's in the list.
If your list is unsorted, you're basically stuck with a sequential search.
Second, you should be changing first or last depending on the comparison. You change last in both cases, which won't end well.
Third, it's not usually a good idea to use standard data type names or functions as variable names. Because Python treats classes and functions as first-class objects, you can get into a situation where your bindings break things:
>>> a_tuple = (1, 2) ; a_tuple
(1, 2)
>>> list(a_tuple) # Works.
[1, 2]
>>> list = list(a_tuple) ; list # Works, unintended consequences.
[1, 2]
>>> another_list = list(a_tuple) # No longer works.
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'list' object is not callable
Covering those issues, your code would look something like this (slightly reorganised in the process):
my_list = [3, 15, 21, 27, 39, 43, 56, 73, 84, 98]
found = False
first, last = 0, len(my_list) - 1
searchValue = int(input("Which number are you looking for? "))
while not found:
if first > last:
break
mid = (first + last) // 2
if my_list[mid] == searchValue:
found = True
else:
if my_list[mid] > searchValue:
last = mid - 1
else:
first = mid + 1
if found:
print("Your number was found at location", mid)
else:
print("The number does not exist within the list")
That works, according to the following transcript:
pax> for i in {1..6}; do echo; python prog.py; done
Which number are you looking for? 3
Your number was found at location 0
Which number are you looking for? 39
Your number was found at location 4
Which number are you looking for? 98
Your number was found at location 9
Which number are you looking for? 1
The number does not exist within the list
Which number are you looking for? 40
The number does not exist within the list
Which number are you looking for? 99
The number does not exist within the list
First of all, do not use any reserved word (here list) to name your variables. Secondly, you have a logical error in the following lines:
if list[mid] > searchValue:
last = mid - 1
else:
last = mid + 1
In the last line of the above snippet, it should be first = mid + 1
There are very good answers to this question, also you can consider this simpler version adapted to your case:
my_list = [3, 15, 21, 27, 39, 43, 56, 73, 84, 98] # sorted!
left, right = 0, len(my_list) # [left, right)
search_value = int(input("Which number are you looking for? "))
while left + 1 < right:
mid = (left + right) // 2
if my_list[mid] <= search_value:
left = mid
else:
right = mid
if my_list[left] == search_value: # found!
print("Your number was found at location", left)
else:
print("The number does not exist within the list")
The problem with your function is that in Binary Search the array or the list needs to be SORTED because it's one of the most important principal of binary search, i made same function working correctly for you
#low is the first index and high is the last index, val is the value to find, list_ is the list, you can leave low as it is
def binary_search(list_: list, val,high: int, low: int = 0):
mid = (low+high)//2
if list_[mid] == val:
return mid
elif list_[mid] <= val:
return binary_search(list_, val, high+1)
elif list_[mid] >= val:
return binary_search(list_, val, high, low-1)
and now here's the output
>>> binary_search(list_, 21, len(list_)-1)
>>> 2
what will happen here is that first it will calculate the middle index of the list, which i think of your list is 5, then it will check whether the middle value is equal to the value given to search, and then return the mid index, and if the mid index is smaller than the value, then we will tell it to add one to high index, and we did the comparison with index and value because as i told you, list needs to be sorted and this means if index is greater or equal to the mid index then the value is also surely greater than the middle value, so now what we will do is that we will call the same function again but this time with a higher high which will increase the mid point and if this time middle index is equal to value, then its gonna return the value and going to do this untill mid is equal to value, and in the last elif it says if middle value is greater than value, we will call same function again but lower the low i.e which is 0 and now -1, which will reduce the mid point and this whole process will continue untill mid is equal to value
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)
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
I'm trying to print the sum of a list generated through raw_input.
The numbers in the list must be between 1 and 1000, inclusive. The length of the list must be below 1000.
here is my code thus far:
initial_list = raw_input()
integer= initial_list.split(' ')
if len(integer) <= 1000:
for i in integer:
if i >= 1 and i<=1000:
actual_integer = map( int, integer)
print sum(actual_integer)
This does not print anything. Any suggestions and/or alternatives?
If I understand your objective correctly, you've got all the right ideas, you just need to re-order your logic a little and make sure you are clear in your head about when you're dealing with a list of values and when you're dealing with a single value.
You may wish to consider your variable naming, too, as good names can help you keep track of whether the variable has a type with multiple values or single values. I've updated your code with that in mind
initial_list = raw_input().split() # split(' ') works, but you don't actually need the ' ',
# split() on its own does the same job here
if len(initial_list) <= 1000:
actual_integers = map(int, initial_list) #Moved to here. Note that
#actual_integers is a list
#so for the following comparison
#you just want to look at the max
#and min (individual values)
if min(actual_integers) >= 1 and max(actual_integers) <= 1000:
print sum(actual_integers)
else: #Just added two nice messages to the user if it doesn't print out.
print 'integers must be in range 1-1000 inclusive'
else:
print 'your list must have 1000 integers or fewer'
This code here does what you need but there is no error checking.
initial_list = raw_input() # there should be some prompt text
# no error checking
integer = initial_list.split(' ')
# no output for lists > 1000
if len(integer) <= 1000:
print sum(filter(lambda i: 0 < i <= 1000, map(int, integer)))
The output
$ python test.py
1 2 3 1500 0
6
If I understand your question correctly, this maybe what you're looking for.
This code will prompt the input and append the input to the list lst until lst will have 1000 elements. It will only take an input if the input is a number between 1 and 1000 and it will give you the sum after every input.
lst = []
while len(lst) <= 999:
initial_list = raw_input('Input numbers between 1 and 1000:')
if initial_list.isdigit() and int(initial_list) <= 1000 and int(initial_list) >= 1:
lst.append(int(initial_list))
print 'List:', lst #prints the list
total = sum(lst)
print 'List Sum:', total #prints the list sum
else:
print 'Input must be numbers between 1 and 1000'
Output:
Input numbers between 1 and 1000:12
List: [12]
List Sum: 12
Input numbers between 1 and 1000:45
List: [12, 45]
List Sum: 57
Input numbers between 1 and 1000:156
List: [12, 45, 156]
List Sum: 213
Input numbers between 1 and 1000:256
List: [12, 45, 156, 256]
List Sum: 469
Input numbers between 1 and 1000:
Please help for task with the list in Python my logic is bad works:( .
This is full text of task: Write a program that takes a list of
numbers on one line and displays the values in a single row, are
repeated in it more than once.
To solve the problem can be useful sort method list.
The procedure for withdrawal of repetitive elements may be arbitrary.
My beginning code is :
st = (int(i) for i in input().split())
ls = []
for k in st:
if k == k + 1 and k > 1:
Task is : if we have replay value in list we must print it. We only can use sort() method and without any modules importing.
Results Examples:
Sample Input 1:
4 8 0 3 4 2 0 3
Sample Output 1:
0 3 4
Sample Input 2:
10
Sample Output 2:
Sample Input 3:
1 1 2 2 3 3
Sample Output 3:
1 2 3
This code isn't run( sort() function doesn't want sort my_list. But I must input values like my_list = (int(k) for k in input().split())
st = list(int(k) for k in input())
st.sort()
for i in range(0,len(st)-1):
if st[i] == st[i+1]:
print(str(st[i]), end=" ")
my_list = (int(k) for k in input().split())
After running this line, my_list is a generator, something that will create a sequence - but hasn't yet done so. You can't sort a generator. You either need to use []:
my_list = [int(k) for k in input().split()]
my_list.sort()
which makes my_list into a list from the start, instead of a generator, or:
my_list = list(int(k) for k in input().split()))
my_list.sort()
gather up the results from the generator using list() and then store it in my_list.
Edit: for single digits all together, e.g. 48304, try [int(k) for k in input()]. You can't usefully do this with split().
Edit: for printing the results too many times: make the top of the loop look backwards a number, like this, so if it gets to the second or third number of a repeating number, it skips over and continues on around the loop and doesn't print anything.
for i in range(0,len(st)-1):
if st[i] == st[i-1]:
continue
if st[i] == st[i+1]:
print...
st = (int(i) for i in input().split())
used = []
ls = []
for k in st:
if k in used: # If the number has shown up before:
if k not in used: ls.append(k) # Add the number to the repeats list if it isn't already there
else:
used.append(k) # Add the number to our used list
print ' '.join(ls)
In summary, this method uses two lists at once. One keeps track of numbers that have already shown up, and one keeps track of second-timers. At the end the program prints out the second-timers.
I'd probably make a set to keep track of what you've seen, and start appending to a list to keep track of the repeats.
lst = [num for num in input("prompt ").split()]
s = set()
repeats = []
for num in lst:
if num in s and num not in repeats:
repeats.append(num)
s.add(num)
print ' '.join(map(str,repeats))
Note that if you don't need to maintain order in your output, this is faster:
lst = [num for num in input("prompt ").split()]
s = set()
repeats = set()
for num in lst:
if num in s:
repeats.add(num)
s.add(num)
print ' '.join(map(str, repeats))
Although if you can use imports, there's a couple cool ways to do it.
# Canonically...
from collections import Counter
' '.join([num for num,count in Counter(input().split()).items() if count>1])
# or...
from itertools import groupby
' '.join([num for num,group in groupby(sorted(input().split())) if len(list(group))>1])
# or even...
from itertools import tee
lst = sorted(input('prompt ').split())
cur, nxt = tee(lst)
next(nxt) # consumes the first element, putting it one ahead.
' '.join({cur for (cur,nxt) in zip(cur,nxt) if cur==nxt})
this gives the answers you're looking for, not sure if it's exactly the intended algorithm:
st = (int(i) for i in input().split())
st = [i for i in st]
st.sort()
previous = None
for current in st:
if ((previous is None and current <= 1)
or (previous is not None and current == previous + 1)):
print(current, end=' ')
previous = current
>>> "4 8 0 3 4 2 0 3"
0 3 4
>>> "10"
>>> "1 1 2 2 3 3"
1 2 3
updated to:
start with st = (int(i) for i in input().split())
use only sort method, no other functions or methods... except print (Python3 syntax)
does that fit the rules?