What's x for x in input()?

Question

I am new to coding and is trying to solve this python question

Question: Write a program that calculates and prints the value according to the given formula: Q = Square root of [(2 * C * D)/H] Following are the fixed values of C and H: C is 50. H is 30. D is the variable whose values should be input to your program in a comma-separated sequence.

Example Let us assume the following comma separated input sequence is given to the program:

100,150,180

The output of the program should be:

18,22,24

Hints: If the output received is in decimal form, it should be rounded off to its nearest value (for example, if the output received is 26.0, it should be printed as 26) In case of input data being supplied to the question, it should be assumed to be a console input.

This is the solution given. I have not seen 'x for x in input()'expression, may I know what does this expression do ?

import math
c=50
h=30
value = []
items=[x for x in input().split(',')]
for d in items:
    value.append(str(int(round(math.sqrt(2*c*float(d)/h)))))
print (','.join(value))

This is my own solution but somehow I got a syntax error.

def sr(D):
    For item in D:
        return ((2*50*D)/30)**0.5
try:    
    a=int(input())
    j=a.split(",")
    print(sr(j))
except:
    print('Please enter an integers or intergers seperated by comma')

Possible duplicate of [What does "list comprehension" mean? How does it work and how can I use it?](https://stackoverflow.com/questions/34835951/what-does-list-comprehension-mean-how-does-it-work-and-how-can-i-use-it) — Mr. T, Mar 18 '18 at 06:15

score 0 · Answer 1 · answered Mar 18 '18 at 04:49

The x is just a variable that gets assigned to the input that comes in via the input() function.

If you're aware of C style language (or Java), it's similar to

for(int i=0;<some_condition>;<some_operation>){}

This is just a condensed, pythonic and easy to read way to do this.

You can read more Python loops here

https://wiki.python.org/moin/ForLoop

What's x for x in input()?

1 Answers1