Question

I am trying to create a triangle of numbers using Python from user input. I have written a code but not sure how to do one thing in python. I would like to change the print(“Next row”) to the respective row accordingly. How do i do that?

Code:

numstr= raw_input("please enter the height:")
rows = int( )
def triangle(rows):
    for rownum in range (rows)
        PrintingList = list()
        print("Next row")
        for iteration in range (rownum):
            newValue = raw_input("Please enter the next number:")
            PrintingList.append(int(newValue))
            print() 

Is there any mistakes in my code? or is there any suggestions for improvements? please do tell me.. thanks…

Answer 1

I am not exactly sure what is desired behaviour for your program, but here is my guess:

numstr= raw_input("please enter the height:")

rows = int(numstr) # --> convert user input to an integer
def triangle(rows):
    PrintingList = list()
    for rownum in range (1, rows + 1): # use colon after control structure to denote the beginning of block of code        
        PrintingList.append([]) # append a row
        for iteration in range (rownum):
            newValue = raw_input("Please enter the next number:")
            PrintingList[rownum - 1].append(int(newValue))
            print() 

    for item in PrintingList:
      print item
triangle(rows)

And here is the output:

please enter the height:3
Please enter the next number:1
()
Please enter the next number:2
()
Please enter the next number:3
()
Please enter the next number:4
()
Please enter the next number:5
()
Please enter the next number:4
()
[1]
[2, 3]
[4, 5, 4]