I am currently learning python, I just have one little question over here.
I used for loop and getting a result below.
Here is my code:
def psuedo_random(multiplier, modulus, X_0, x_try):
for i in range(x_try):
place_holder = []
count = []
next_x = multiplier * X_0 % modulus
place_holder.append(next_x)
X_0 = next_x
for j in place_holder:
j = j/modulus
count.append(j)
print(count)
Result:
[0.22021484375]
[0.75439453125]
[0.54443359375]
[0.47705078125]
Can we somehow change it into something like this?
[0.22021484375, 0.75439453125, 0.54443359375, 0.47705078125]
After you initialized a list, you can use append function in the loop.
initialize a list where you want to list these numbers
mylist = []
use this function in your for loop
for i in .....:
mylist.append(i)
It's simple. Do not initialize your list inside the loop. Just place it outside.
Related
temp = "75.1,77.7,83.2,82.5,81.0,79.5,85.7"
I am stuck in this assignment and unable to find a relevant answer to help.
I’ve used .split(",") and float()
and I am still stuck here.
temp = "75.1,77.7,83.2,82.5,81.0,79.5,85.7"
li = temp.split(",")
def avr(li):
av = 0
for i in li:
av += float(i)
return av/len(li)
print(avr(li))
You can use sum() to add the elements of a tuple of floats:
temp = "75.1,77.7,83.2,82.5,81.0,79.5,85.7"
def average (s_vals):
vals = tuple ( float(v) for v in s_vals.split(",") )
return sum(vals) / len(vals)
print (average(temp))
Admittedly similar to the answer by #emacsdrivesmenuts (GMTA).
However, opting to use the efficient map function which should scale nicely for larger strings. This approach removes the for loop and explicit float() conversion of each value, and passes these operations to the lower-level (highly optimised) C implementation.
For example:
def mean(s):
vals = tuple(map(float, s.split(',')))
return sum(vals) / len(vals)
Example use:
temp = '75.1,77.7,83.2,82.5,81.0,79.5,85.7'
mean(temp)
>>> 80.67142857142858
My goal was to create a method that would take an array as parameter, and output the sum of the min() value of each of its subarrays. However, I really don’t understand what’s wrong with my list comprehension.
class Solution(object):
def sumSubarrayMins(self, arr):
s = 0
self.subarrays = [arr[i:j] for i in range(j-1,len(arr))for j in range(1,len(arr)+1)]
for subarray in self.subarrays:
s += min(subarray)
return s
sol = Solution()
sol.sumSubarrayMins([3,1,2,4])
I often try debugging with python tutor but it is really no help in this case.
Your subarray calculation logic is wrong. You are trying to use j in the first loop, before you define it. Try this:
self.subarrays = [arr[i:j] for i in range(0, len(arr)) for j in range(i+1, len(arr)+1)]
The task is:
User enters a number, you take 1 number from the left, one from the right and sum it. Then you take the rest of this number and sum every digit in it. then you get two answers. You have to sort them from biggest to lowest and make them into a one solid number. I solved it, but i don't like how it looks like. i mean the task is pretty simple but my code looks like trash. Maybe i should use some more built-in functions and libraries. If so, could you please advise me some? Thank you
a = int(input())
b = [int(i) for i in str(a)]
closesum = 0
d = []
e = ""
farsum = b[0] + b[-1]
print(farsum)
b.pop(0)
b.pop(-1)
print(b)
for i in b:
closesum += i
print(closesum)
d.append(int(closesum))
d.append(int(farsum))
print(d)
for i in sorted(d, reverse = True):
e += str(i)
print(int(e))
input()
You can use reduce
from functools import reduce
a = [0,1,2,3,4,5,6,7,8,9]
print(reduce(lambda x, y: x + y, a))
# 45
and you can just pass in a shortened list instead of poping elements: b[1:-1]
The first two lines:
str_input = input() # input will always read strings
num_list = [int(i) for i in str_input]
the for loop at the end is useless and there is no need to sort only 2 elements. You can just use a simple if..else condition to print what you want.
You don't need a loop to sum a slice of a list. You can also use join to concatenate a list of strings without looping. This implementation converts to string before sorting (the result would be the same). You could convert to string after sorting using map(str,...)
farsum = b[0] + b[-1]
closesum = sum(b[1:-2])
"".join(sorted((str(farsum),str(closesum)),reverse=True))
I'm trying to write a code that will return common values from a dictionary based on a list of words.
Example:
inp = ['here','now']
dict = {'here':{1,2,3}, 'now':{2,3}, 'stop':{1, 3}}
for val in inp.intersection(D):
lst = D[val]
print(sorted(lst))
output: [2, 3]
The input inp may contain any one or all of the above words, and I want to know what values they have in common. I just cannot seem to figure out how to do that. Please, any help would be appreciated.
The easiest way to do this is to just count them all, and then make a dict of the values that are equal to the number of sets you intersected.
To accomplish the first part, we do something like this:
answer = {}
for word in inp:
for itm in word:
if itm in answer:
answer[itm] += 1
else:
answer[itm] = 1
To accomplish the second part, we just have to iterate over answer and build an array like so:
answerArr = []
for i in answer:
if (answer[i] == len(inp)):
answerArr.append(i)
i'm not certain that i understood your question perfectly but i think this is what you meant albeit in a very simple way:
inp = ['here','now']
dict = {'here':{1,2,3}, 'now':{2,3}, 'stop':{1, 3}}
output = []
for item in inp:
output.append(dict[item])
for item in output:
occurances = output.count(item)
if occurances <= 1:
output.remove(item)
print(output)
This should output the items from the dict which occurs in more than one input. If you want it to be common for all of the inputs just change the <= 1 to be the number of inputs given.
So I'm writing a python code and I want to have a for loop that counts from the the 2nd item(at increment 1). The purpose of that is to compare if there are any elements in the list that match or are included in the first element.
Here's what I've got so far:
tempStr = list500[0]
for item in list500(1,len(list500)):
if(tempStr in item):
numWrong = numWrong - 1
amount540 = amount540 - 1
However the code doesn't work because the range option doesn't work for lists. Is there a way to use range for a list in a for loop?
You can get a subset of the list with the code below.
tempStr = list500[0]
for item in list500[1:]:
if(tempStr in item):
numWrong = numWrong - 1
amount540 = amount540 - 1
The [1:] tells Python to use all elements of the array except for the first element. This answer has more information on list slicing.
Use a function:
search_linear(mainValues, target)
This is the algorithm you are looking for: http://en.wikipedia.org/wiki/Linear_search
All you need to do is set the starting point equal to +1 in order to skip your first index, and than use array[0] to call your first index as the target value.
def search_linear(MainValues, Target):
result = []
for w in Target:
if (search_linear(MainValues, w) < 0):
result.append(w)
return result