View source for Transforming a list of data in Python

Exercise to be typed in ipython.

To test, you can use the ''range'' function to get some "sample" data to work with:

<source lang="python">
data = range(100)

for d in data:
    print d
</source>

Imagine you want to multiply each number by 17.

<source lang="python">
for d in data:
    print d*17
</source>

== Iterate & Append to a new list ==

A general purpose technique to translate the items of one list to another is to:<br>
1. Create a new empty list<br>
2. Iterate over the original list<br>
3. Use the list.append function to add (transformed) items onto the new list

<source lang="python">
pp = []
for d in data:
    pp.append(d)
pp

pp = []
for d in data:
    pp.append(d*17)
pp
</source>

== List comprehensions ==

Python also supports a more mathematically inspired notation called List Comprehensions. The result is more compact, and may or may not be easier to read.

<source lang="python">
p = range(100)
pp = [x*17 for x in p]
</source>


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