Question

2011 Problem set #2 , problem 1.
hey there i have started this problem. at the moment i am thinking of how i can extract the information out. So it can then be processed. There are two pieces of information , the index of the number in the tuple which gives the power and the actual value , which gives the co efficent.
So if i have
mytuple = (1,2,3)
this will give
my_power = (0,1,2)
my coefficent = ( 1,2,3)
i am strugggle to extract the index information. does anyone have any ideas , thanks jack

Answer 1

you mean you want to be able to find which index has the 3 or what?
I'm not sure I understand

Answer 2

do you just want to be able to create ` my_power = (0,1,2) ` from ` my_coefficient = (1,2,3) ` ?

Answer 3

sorry i am probabaly not explaining what i mean very well , what i want is a way of extracting the index sequence of a list into actual numbers inside a list . it is this index information that i want . So if my list was my_list = ( jack , john , joe ) i like my new list to be my_new_list = (0,1,2)

Answer 4

you could do something like
```
my_new_list = ()
for i in range(len(my_list)):
my_new_list += (i,)
```

Answer 5

Hi thank you for this . Intially what i wrote was
for i in(len(poly)):
print i

but got a error message saying ' 'int' object is not iterable' i guess i have to use the range function . Do you have any idea on the theory behind not being able use the code i wrote. Plus how do i get the code i am writing to come up in a box as yours has above. Thanks for your help

Answer 6

Python can only iterate over certain kinds of objects like lists and tuples. I don't think any language can iterate *over* an integer, but in other languages you have `for` loops that look like `while` loops, in that they loop until a certain condition is met. The `for` loops in python work more like `foreach` loops in other languages, in that they specifically iterate over objects in an array.

`range(5)` produces a list `[0,1,2,3,4]` which can then be iterated over by the Python interpreter.

When you did
```
for i in len(poly):
print i
```
you tried to iterate over a single number: the length of the array, which is not allowed.

Answer 7

I will explain grey boxes in private message so the syntax gets ignored

Answer 8

I should point out that `range` only produces a list in Python 2.7. I think it produces a "range object" in Python 3.x, which you then have to convert to a list to iterate over (which is annoying).