# list.py
# The most important feature of the Python language is the list.
# Often, we want to store many values for processing.

# Let's create a new list, and call it L.

L = [5, 4, 7, 3, 2, 6, 1]

# The entire list is called L.  But how do we refer to
# one number in the list?  We use brackets like this:
# L[0] is the first number, L[1] is the 2nd number, etc.

# Let's print the 3rd number:
print "The third number is "
print L[2]

# Let's print all the numbers.

print "Here are all the numbers in the list:"
for number in L:
	print number

# Let's find the sum of all the numbers:

sum = 0
for number in L:
	sum = sum + number
	
	
# Neat trick:  In order to print a number on the same line as the
# message that introduces it, there are 2 strategies:
# 1.  Put a comma after the text, like this:
#       print "The sum is ",
#       print sum
# 2.  Use just one print statement, and use concatenation:
#       print "The sum is " + str(sum)
#     In Python, if you want to print both a number and a string(text)
#       in the same statement, you need to put str() around the number.
#     This is similar to what we did with text functions in Excel.

print "The sum is " + str(sum)