Python questions help

[su29090]

I brought a python book and i'm a beginner and I read and tried to do the questions and I still get it wrong.

How to create a program that reads an uspecified number of integers, that determines how many positive and negative values have been read, and computes the total and average of the input values(not counting zeroes). My program have to end with the input 0 and have to display the average as a floating-point number.


Use nested loops that display the following patterns in separate programs:

1
12
123
1234
12345
123456

123456
12345
1234
123
12
1

     1
    21
   321
  4321
 54321
654321

Write a program that computes the following summation:

1/ 1+square root of 2 + 1/ 1+square root of 2 + square root of 3 + 1/ 1+square root of 3 + square root of 4...+ 1/ 1+square root of 624 + square root of 625

How to  a program to draw a chessboard using range?

Thanks