Creating fibonacci sequence generator (Beginner Python)

raw_input returns a string. So convert d to an integer with:

d = int(d)

One more thing: Do not use for d in range(d). It works but it is awful, unpythonic, whatever.
Try this way for example:

numbers = raw_input("How many numbers would you like to display")

a = 1
b = 1

print a
print b

for d in range(int(numbers)):
    c = a + b 
    print c
    a = b
    b = c

Edit: I complete below the answer with additional code tuning (thanks to commenters):

# one space will separate better visually question and entry in console
numbers = raw_input("How many numbers would you like to display > ")    

# I personnally prefer this here, although you could put it
# as above as `range(int(numbers))` or in `int(raw_input())`
# In a robust program you should use try/except to catch wrong entries
# Note the number you enter should be > 2: you print 0,1 by default
numbers = int(numbers)  

a, b = 0, 1        # tuple assignation
                   # note fibonnaci is 0,1,1,2,3...

print a            # you can write this as print "%i\n%i" % (a, b)
print b            # but I think several prints look better in this particular case.

for d in range(numbers - 2):  # you already printed 2 numbers, now print 2 less
    c = a + b 
    print c
    a, b = b, c    # value swapping.
                   # A sorter alternative for this three lines would be:
                   # `a, b = b, a + b`
                   # `print b` 

Problem

The problem here is that here:

d = raw_input("How many numbers would you like to display")

you assign string from the input into the d variable, and later you pass it to range(). But range() expects expects integers, not strings, and Python does not convert it automatically (it leaves conversion to you).

Solution

The solution is to convert result of raw_input() into int like that:

d = int(raw_input("How many numbers would you like to display"))

and everything will work unless you provide non-integer.

But there is better (shorter, more efficient, more encapsulated) method of generating Fibonacci numbers (see below).

Better method of generating Fibonacci numbers

I believe this is the best (or nearly the best) solution:

def fibo(n):
    a, b = 0, 1
    for i in xrange(n):
        yield a
        a, b = b, a + b

This is a generator, not a simple function. It is very efficient, its code is short and does not print anything, but you can print its result like that:

>>> for i in fibo(20):
    print i,


0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181

or convert it into a list like that:

>>> list(fibo(20))
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181]

Applying the above in your case

After applying the above to your code, it could look like this:

def fibo(n):
    a, b = 0, 1
    for i in xrange(n):
        yield a
        a, b = b, a + b

d = int(raw_input("How many numbers would you like to display"))
for i in fibo(d):
    print i

Does it answer your question?

You have to convert the input to a number, like this:

d = int(raw_input("How many numbers would you like to display: "))

Also, just for fun, the fibonacci sequence can be expressed more succinctly:

a, b = 0, 1
for i in range(d):
    print a
    a, b = b, a+b

raw_input returns string type.You need to convert it to int.

>>> x = raw_input()
2
>>> x
'2'
>>> type(x)
<type 'str'>

and range function requires int as an argument not string.

Thats why when i do

>>> range(x)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: range() integer end argument expected, got str.

So, change it to

for x in range(int(d)):

Simpler method:

a = [0,1]
for n in range(1,41):
  a.append(a[n]+a[n-1])
  print a[-1]

1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 10946 17711 28657 46368 75025 121393 196418 317811 514229 832040 1346269 2178309 3524578 5702887 9227465 14930352 24157817 39088169 63245986 102334155 165580141

I see many over complicated Fibonacci Sequence programs so I just did this with a while loop; changing the number after the while loop

a = 0 b = 1 while a <= 1000000000: #Changing this number will change how long the sequence goes on for print(a) print(b) a = a+b b = b+a I know this isn't your program but it is a very basic version; I hope this helps :)