For count in range python

range[a, b] returns a list of b - a values, while [a, b] is a tuple with only two values.

To solve your problem you could do e.g.

for x in range[a, b + 1]:  # +1 to include the end of the range in the list
    x = x - a + 1;  # Make x start at 1
    ...

Or

for x in range[1, b - a + 2]:  # +1 to include end of range, +1 again since range start at 1
    ...

Or [as noted by DeepSpace]

for x in range[b - a + 1]:  # +1 to include the end of the range
    x = x + 1  # Since range should start at 1
    ...

The range[] Function

To loop through a set of code a specified number of times, we can use the range[] function,

The range[] function returns a sequence of numbers, starting from 0 by default, and increments by 1 [by default], and ends at a specified number.

Note that range[6] is not the values of 0 to 6, but the values 0 to 5.

The range[] function defaults to 0 as a starting value, however it is possible to specify the starting value by adding a parameter: range[2, 6], which means values from 2 to 6 [but not including 6]:

The range[] function defaults to increment the sequence by 1, however it is possible to specify the increment value by adding a third parameter: range[2, 30, 3]:

Example

Increment the sequence with 3 [default is 1]:

for x in range[2, 30, 3]:
  print[x]

Try it Yourself »

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There are two types of loops in Python, for and while.

The "for" loop

For loops iterate over a given sequence. Here is an example:

primes = [2, 3, 5, 7]
for prime in primes:
    print[prime]

For loops can iterate over a sequence of numbers using the "range" and "xrange" functions. The difference between range and xrange is that the range function returns a new list with numbers of that specified range, whereas xrange returns an iterator, which is more efficient. [Python 3 uses the range function, which acts like xrange]. Note that the range function is zero based.

# Prints out the numbers 0,1,2,3,4
for x in range[5]:
    print[x]

# Prints out 3,4,5
for x in range[3, 6]:
    print[x]

# Prints out 3,5,7
for x in range[3, 8, 2]:
    print[x]

"while" loops

While loops repeat as long as a certain boolean condition is met. For example:

# Prints out 0,1,2,3,4

count = 0
while count < 5:
    print[count]
    count += 1  # This is the same as count = count + 1

"break" and "continue" statements

break is used to exit a for loop or a while loop, whereas continue is used to skip the current block, and return to the "for" or "while" statement. A few examples:

# Prints out 0,1,2,3,4

count = 0
while True:
    print[count]
    count += 1
    if count >= 5:
        break

# Prints out only odd numbers - 1,3,5,7,9
for x in range[10]:
    # Check if x is even
    if x % 2 == 0:
        continue
    print[x]

Can we use "else" clause for loops?

Unlike languages like C,CPP.. we can use else for loops. When the loop condition of "for" or "while" statement fails then code part in "else" is executed. If a break statement is executed inside the for loop then the "else" part is skipped. Note that the "else" part is executed even if there is a continue statement.

Here are a few examples:

# Prints out 0,1,2,3,4 and then it prints "count value reached 5"

count=0
while[count