User is asked to input numbers until certain value is met

[Hafiz75]

Is there a way to asked the user to input a number of there choice. Let’s take 4 for example. And that number is the number of lines. And the user has to input numbers or characters they want in each line. Let’s say on line 1 then enter AADD123. Then the program keeps asking the user to input what they want on each line until it reaches the number they have entered. Which for our example is 4 lines of numbers.

The  program I would like to us in Python 3

[Slottr]

Sure you can. How you'll do it depends on the language though.

[Hafiz75]

Just now, Slottr said:

Sure you can. How you'll do it depends on the language though.

Python 

[Mira Yurizaki]

Sure.

1. Ask them how many lines they want, store this in a variable
2. Use a loop with the exit condition based on the variable (e.g., a while-loop with the exit condition being variable > 0 and decrement the variable at the end of the loop)
3. In the loop, keep asking for whatever you wanted

[Hafiz75]

Just now, Mira Yurizaki said:

Sure.

1. Ask them how many lines they want, store this in a variable
2. Use a loop with the exit condition based on the variable
3. In the loop, keep asking for whatever you wanted

Thanks for the help but I still can’t wrap my head around the question. I’ve been sitting down for 1 hour and still had zero idea. That’s why I came to Linus Tech Tips Forum for someone for help with the code.

[Hafiz75]

3 minutes ago, Mira Yurizaki said:

Sure.

1. Ask them how many lines they want, store this in a variable
2. Use a loop with the exit condition based on the variable (e.g., a while-loop with the exit condition being variable > 0 and decrement the variable at the end of the loop)
3. In the loop, keep asking for whatever you wanted

Could you help me with the code step by step. I’ve done the first part.

 

1.lines= int(input(“How many lines do you want”))

[Mira Yurizaki]

Just now, Safeer Hafiz said:

Could you help me with the code step by step. I’ve done the first part.

 

1.lines= int(input(“How many lines do you want”))

What do you know about loops?

[Mira Yurizaki]

Also I believe Python throws an exception if you feed int() a non-number input. So you need to account for that.

 

I believe strings have a function called isdigit that you can use to verify the input is a number.

[Hafiz75]

13 minutes ago, Mira Yurizaki said:

What do you know about loops?

I literally have no idea how do do this part because my organs will have to store the numbers that are being inputed. Please could you tech me how this is done. 

[Mira Yurizaki]

Just now, Safeer Hafiz said:

I literally have no idea how do do this part because my organs will have to store the numbers that are being inputed. Please could you tech me how this is done. 

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

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

 

Also since I mentioned "exception": https://docs.python.org/3/tutorial/errors.html

[Hafiz75]

5 minutes ago, Mira Yurizaki said:

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

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

 

Also since I mentioned "exception": https://docs.python.org/3/tutorial/errors.html

Please could you just summaries all of that for me. Much appreciated 

[Mira Yurizaki]

Just now, Safeer Hafiz said:

Please could you just summaries all of that for me. Much appreciated 

You should really read about loops, because they are a fundamental element of programming.

 

As for exceptions, it's just a way for the program to declare an input, even though technically it's what something asked for, cannot produce the desired result. For example int() accepts some data, but if it cannot actually convert the data into an integer, it throws an exception. So if you feed int() "123abcd", it will throw an exception because it cannot convert the letters into numbers. The driving principle for using exceptions in Python is "it's easier to ask for forgiveness than permission."

 

Either way, the code that you have as-is will cause the app to break if you input something other than a number, and you should account for this.

[Hafiz75]

6 minutes ago, Mira Yurizaki said:

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

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

 

Also since I mentioned "exception": https://docs.python.org/3/tutorial/errors.html

I’ve read through the pages but they dint help me with what I’m looking for. Because I have to store the number that user has imputed in a variable.

[Mira Yurizaki]

Just now, Safeer Hafiz said:

I’ve read through the pages but they dint help me with what I’m looking for. Because I have to store the number that user has imputed in a variable.

Which you already did, so now we have to use the variable to repeatedly ask the user to input something. Loops are the best way to do this.

[Hafiz75]

1 minute ago, Mira Yurizaki said:

Which you already did, so now we have to use the variable to repeatedly ask the user to input something. Loops are the best way to do this.

Yes but when I loop it, it will to write over the variable. I want o to create new variable.

[Mira Yurizaki]

1 minute ago, Safeer Hafiz said:

Yes but when I loop it, it will to write over the variable. I want o to create new variable.

Look at the loop pages again, one of them will let you do what you want to keep track of how many times the loop has executed.

[Hafiz75]

1 minute ago, Mira Yurizaki said:

Look at the loop pages again, one of them will let you do what you want to keep track of how many times the loop has executed.

Please could you indicate where about that would be. For loops or while loops page

 

 

[Hafiz75]

5 minutes ago, Mira Yurizaki said:

Look at the loop pages again, one of them will let you do what you want to keep track of how many times the loop has executed.

I’ve read both pages but still can’t find what your on about. Please could you just explain to me.

[Hafiz75]

8 minutes ago, Mira Yurizaki said:

Look at the loop pages again, one of them will let you do what you want to keep track of how many times the loop has executed.

Oh. I don’t think your going to reply now. . I’ll find someone else how can help me.

[Mira Yurizaki]

2 minutes ago, Safeer Hafiz said:

I’ve read both pages but still can’t find what your on about. Please could you just explain to me.

Here's an example:

foobar = 10

for x in xrange(0, foobar, 1):
  print x

 

[Hafiz75]

Just now, Mira Yurizaki said:

Here's an example:

foobar = 10

for x in xrange(0, foobar, 1):
  print x

 

???. There no inputs. 

[Mira Yurizaki]

1 minute ago, Safeer Hafiz said:

???. There no inputs. 

Okay, level with me

 

Do you want me to teach you the basics of programming so you can solve this on your own, or do you just want me to provide the source code that'll do what you want?

[Hafiz75]

1 minute ago, Mira Yurizaki said:

Okay, level with me

 

Do you want me to teach you the basics of programming so you can solve this on your own, or do you just want me to provide the source code that'll do what you want?

Second option would be preferred.

[Mira Yurizaki]

5 minutes ago, Safeer Hafiz said:

Second option would be preferred.

 

lines_input = input("Enter number of lines you want: ")

while (str.isdigit(lines_input) == False):
    lines_input = input("Enter number of lines you want: ")

lines = int(lines_input)
user_input = []

for x in range(lines):
    user_input.append(input("Enter some text (Line %d): " % (x + 1)))

for line in user_input:
    print(line)

 

[Ryujin2003]

2 hours ago, Safeer Hafiz said:

Second option would be preferred.

Wow... You literally could've saved the whole entire effort by googling your question and stealing the first thing you find in Stack Overflow.

 

If you don't care to learn, then why are you doing basic homework problems for an entry level course?