Python provides the
for loop in order to iterate over multiple items. There may be different types of items like names, dictionaries, and numbers. The
Python i is a popular variable name used in “for loops”. “Python i” is mostly used to iterate over a list of numbers and these numbers can be also generated with the range() method. The “Python i” name comes from
integer where the
i is used to express integer.
Python i Loop
The Python loop syntax is like below where every iterated item is stored inside a variable which is named as
i for this tutorial.
for i in ITERABLE: CODE
iis the current step value which is assigned from the ITERABLE
- ITERABLE is a list that contains numbers or generators like range().
- CODE is executed for every iteration where the
ivariable is generally used.
Iterate i with List
In the following example, we iterate over a list of integers or numbers. We assign one item from the list to the variable i and then use the variable i inside the for loop body.
for i in [1,2,3,4,5]: r = i+i print(r)
Iterate i with Range
We can use the i variable with for loop by using the
range() method. We use the range method to generate a list of numbers that starts from 0 and stops at 5.
for i in range(5): r = i+i print(r)
Iterate i with Start, Stop
We can use the range() method with i variable by specifying the start and end numbers.
for i in range(1,5): r = i+i print(r)
Iterate i with Start, Stop and Step
Alternatively, we can specify the start, stop and step values for the range() method while using the i variable.
for i in range(1,5,2): r = i+i print(r)
Iterate i Negatively
We can iterate negatively by using the range() method. We specify the step as a negative value like “-1” and also provide the start and stop numbers.
for i in range(5,1,-1): r = i+i print(r)