[split] question about list comprehension

[Armin]

Hello everyone I hope someone can explain this cod to me there is the variable y [ ] – list how this code works. hope I'm not too boring. Here we have an input number but since Python is the default input string then it is a string and if i type 10 for example the result is 6 which is true but do not understand how y takes this number and also what does works hier “.split” bult-in functions and in the next line we attribute the same later to the variable ‘’d’. Thanks a lot in advance

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# calculate Q c = 50 h = 30 # use thi formule Q = square root of [(2*c*d)/h] import math x = [] y = [i for i in input('give me a number: ').split(',')]   # ????? for d in y:     x.append(str(int(round(math.sqrt((2*c*float(d)/h)))))) print(','.join(x))

[Larz60+]

program will remain in for loop until enter button pressed, then contents will be split.
Think of it in its expanded form

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>>> i = input('Give me a number') Give me a number1, 2, 3 >>> y = i.split(',') >>> y ['1', ' 2', ' 3']

Message should specify that numbers should be separated by ',' and terminated on enter

[Armin]

Thanks for your reply what bothers me most about this code is line 7 this part y = [i for i in input ('give me a number:') i know this is list comprehensions but i don't understand it how this line of code number 7 works ??

[Clunk_Head]

Thanks for your reply what bothers me most about this code is line 7 this part y = [i for i in input ('give me a number:') i know this is list comprehensions but i don't understand it how this line of code number 7 works ??

1	[i for i in input('give me a number: ').split(',')]

1 2	number_string = input('give me a number: ') # "1, 2, 3" numbers = number_string.split(',')          #[1, 2, 3]

It's really overkill

1	input('give me a number: ').split(',')

Is functionally equivalent

[rmspacedashrf]

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y = [i for i in input('give me a number: ').split(',')]      ^this is the expression i that will replace every instance of i where the condition is true   y = [i for i in input('give me a number: ').split(',')]        <------> setting up a for loop with i   y = [i for i in input('give me a number: ').split(',')]                 <------------------------------------> this is actually two things stuck together. input() returns string or empty string always. the .split method is something you throw on the end of an object such as a string. the .split() method always returns string, a list of strings or empty string if there is no error from type mismatch or missing arguments. because input() returns a string, input().split is totally fine just like "1,2,3".split(',') also something = "1,2,3" print(something.split(',')) output 1 2 3

for loops work on an object that is iterable. the list ['1', ' 2', ' 3'] is iterable. 1 is not iterable.

[Armin]

Thanks a lot for helping me understand this but now if I enter say 10 in this case the string it will be .split () will be output to '1' and '0' as then in the following line I assign y the value of 10 variables di then inside the formula I get result 6? I apologize in advance if I'm bored, but I've been messing with this code all day and can't handle it completely.
Thank you all very much

[Larz60+]

if I enter say 10 in this case the string it will be .split () will be output to '1' and '0'

That's not how split works.
split requires a delimiter. If none is supplied space is assumed.
the results of a split are returned in a list

remember, the best way to learn is to try.
bring up the python interpreter so you can try for yourself (just type python3 at command line)
some examples:

example 1, no delimiter specified, so default space is used

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>>> string1 = "This is a string" >>> string1.split() ['This', 'is', 'a', 'string']

example 2 specifing a delimiter:

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>>> string2 = "This string has a hyphenated-word in it" >>> string2.split("-") ['This string has a hyphenated', 'word in it'] >>>

useful for separating items delimited with special characters:
example3:

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>>> data = "10/18/2016|ALA|16|970|827|540|2337" >>> dlist = data.split('|') >>> dlist ['10/18/2016', 'ALA', '16', '970', '827', '540', '2337'] >>>

[Clunk_Head]

Are you trying to split something like 752 into [7, 5, 2]?
If so then read about integer math.
You will find the modulo and integer division or particular interest.

[Armin]

Thank you very much

[Armin]

I understand split nouw but what i can't understand is this part of the code in line 7
“y = [i for i in input “
this part of the code and why this code is there because the program works without this part of the code if we put in line 7 above, for example
y = input('give me a number: ').split(',')
we get the same result. I understand that this is the work of codo o comprehensive list but not understood why it's there"i in i for input " in lijn 7.
Thanks in advance