How to make the raw_input prompt automatically read a string from a previous list?

Question

I have created a list like so:

names=["Tom", "Dick", "Harry"]

I want to use these list elements in the prompt for a raw_input.

For example I would like the next line to read: a=raw_input("What is Tom's height?") except that in this form it is hard coded so that the prompt for a will always ask for Tom's height.

I would like the code to be more flexible so that any change to the list element would automatically be updated in the prompt. For example if I changed the list to names=["Matthew", "Sarah", "Jane"] I would like the prompt for a to ask for Matthew's height so that it is always reading the first element of the list.

How can I make it so that the prompt will automatically change if the elements in the list change?

Answer 1

If you want to prompt the user for every name in the list:

names=["Tom", "Dick", "Harry"]
for name in names:
    a = raw_input("What is {}'s height? ".format(name))

EDIT:

To store the results in a list (as per request in comment):

names=["Tom", "Dick", "Harry"]
results = []
for name in names:
    results.append(raw_input("What is {}'s height? ".format(name)))

Answer 2

names=["Tom", "Dick", "Harry"]

a = raw_input("What is %s's height?" % names[0])

Answer 3

What this question boils down to is: How do I have a string that can change based on variables in the program, rather than being just a literal string?

In python, you can do this in a few ways.

One intuitive way is to concatenate (add) strings together.

That would look like this

names=["Tom", "Dick", "Harry"]
a=raw_input("What is " + names[0] + "'s height?")

Another (nicer) way to do this is with the str.format() syntax (also called "new-style string formatting")

names=["Tom", "Dick", "Harry"]
a=raw_input("What is {}'s height?".format(names[0]))

That approach has advantages (and I would recommend it) in that it's more flexible: the arguments that you use (in this case names[0]) don't have to be strings. In this case, both approaches work, since the name is a string anyways. But if, for example, you wanted the changeable part of the string to be an int, the first approach would not work, while the second approach would cast the int to a string and it would work as you would expect.

There are also other ways to do string formatting: C-style string formatting with %, borrowed from sprintf from the C language, although generally the str.format() is considered to be a replacement for that.

For sake of completeness, there's a final brand-new way to do string formatting, but it's only in Python 3.6.