Given a range of first 10 numbers, Iterate from start number to the end number and print the sum of the current number and previous number

Question

I'm trying to write Python code for the above problem and getting an error code. I would appreciate help:

num = list(range(10))
previousNum = 0
for i in num:
    sum = previousNum + i
    print('Current Number '+ str(i) + 'Previous Number ' + str(previousNum) + 'is ' + str(sum)
    previousNum=i

This is the error I get:

File "<ipython-input-40-6f1cd8f8f1d7>", line 6
    previousNum=i
              ^
SyntaxError: invalid syntax

Please, be more specific. What language are you using? The syntax errors are very linked to the language... — Roberto C. Rodriguez-Hidalgo, Apr 13 '20 at 04:46
You're just missing the closing bracket at the end of your print statement - after str(sum). Should be + str(sum)) — Stidgeon, Apr 13 '20 at 04:54
huh - yes it worked - i guess i was thrown off by the error message as it was pointing at line 6 (the last line) and previousNum=i. Any idea why would it be doing so insteading of pointing to the missing bracket in line 5 - thanks — Haseeb Haque, Apr 13 '20 at 05:02

score 1 · Accepted Answer · answered Apr 13 '20 at 05:25

Looks to be a simple syntax error in line 5.

You're missing a closing parenthesis ")" at the end of your print function.

For example:

num = list(range(10))
previousNum = 0
for i in num:
    sum = previousNum + i
    print('Current Number '+ str(i) + 'Previous Number ' + str(previousNum) + 'is ' + str(sum)) # <- This is the issue.
    previousNum=i

Also, here are 3 pointers to improve your code that might be useful for you:

First off, Python uses snake case for it's language as described in PEP8, so instead of typing "previousNum" you should use "previous_num", so we'll start with that.
Storing list(range(1)) in this instance isn't needed. You can just use the ```range(10)''' function in place of having a stored list of ranges.
f strings are much more readable ways of doing String Concatenation (adding strings together).

With these your code will look like this:

previous_num = 0
for i in range(10):
    sum = previous_num + i
    print(f'Current number {i} Previous Number {previous_num} is {sum}')
    previous_num = i

Happy coding!

score 0 · Answer 2 · answered Apr 13 '20 at 05:01

0

sum = 0
for idx in range(10):
    print(f'current number = {idx}')
    if idx != 0:
        sum += idx
        print(f'cumul. sum = {sum}')

answered Apr 13 '20 at 05:01

Jesse Bluestein

47
5

3

Please don't post only code as an answer, but also provide an explanation what your code does and how it solves the problem of the question. Answers with an explanation are usually of higher quality, and are more likely to attract upvotes. – ilke444 Apr 13 '20 at 06:42

Mittenchops · Answer 3 · 2020-04-13T23:42:53.067

0

Welcome to Stackoverflow. There's always functional python:

>>> list(map( lambda x: x[0] + x[1], zip(range(0,10), range(1,11))))
[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]

Or if you meant a cumulative sum of predecessors, like a reduce:

>>> [sum(range(xs)) for xs in range(1,11)]
[0, 1, 3, 6, 10, 15, 21, 28, 36, 45]

This used to be easier in python 2, before range, filter, and map were turned into iterators.

edited Apr 13 '20 at 23:42

answered Apr 13 '20 at 05:45

Mittenchops

18,633
33
128
246

Anoop Bhat · Answer 4 · 2020-09-26T17:04:56.630

0

for i in range(1,10+1):
   print(i+i-1, end=' ')

Here it iterates from 1 to 10 inclusively. It prints the value of sum of current value of i and the previous value that is i-1

edited Sep 26 '20 at 17:04

answered Sep 26 '20 at 16:59

Anoop Bhat

1
1

Given a range of first 10 numbers, Iterate from start number to the end number and print the sum of the current number and previous number

4 Answers4