How do you count inside a loop in python?
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Is there a way to know within the loop how many times I've been looping so far? For instance, I want to take a list and after I've processed ten elements I want to do something with them. The alternatives I thought about would be something like:
Or:
Is there a better way (just like the
Mateen Ulhaq 22.1k16 gold badges86 silver badges126 bronze badges asked Jul 1, 2010 at 22:59
1 The pythonic way is to use
Mateen Ulhaq 22.1k16 gold badges86 silver badges126 bronze badges answered Jul 1, 2010 at 23:02
Nick BastinNick Bastin 29.4k7 gold badges57 silver badges77 bronze badges 1 Agree with Nick. Here is more elaborated code.
I have commented out the count variable in your code. answered Oct 16, 2013 at 8:34
Vikram GargVikram Garg 1,2791 gold badge8 silver badges8 bronze badges 1 Using zip function we can get both element and index.
See also : Python.org
Hans Ginzel 7,0833 gold badges22 silver badges22 bronze badges answered Mar 14, 2020 at 10:33
0 I know rather old question but....came across looking other thing so I give my shot:
answered Jan 24, 2017 at 22:49
hephestoshephestos 4625 silver badges19 bronze badges 0 Not the answer you're looking for? Browse other questions tagged python for-loop or ask your own question.Watch Now This tutorial has a related video course created by the Real Python team. Watch it together with the written tutorial to deepen your understanding: Looping With Python enumerate() In Python, a In this tutorial, you’ll see how to:
Let’s get started! Iterating With for Loops in PythonA >>>
In this example, Next, you print Now imagine that, in addition to the value itself, you want to print the index of the item in the list to the screen on every iteration. One way to approach this task is to create a variable to store the index and update it on each iteration: >>>
In this example, >>>
In this example, Another common way to approach this problem is to use >>>
In this example, With this example, one common bug that can occur is when you forget to update This example is also somewhat restricted because Fortunately, Python’s
Using Python’s enumerate()You can use >>>
When you use
Just like with a normal With Python’s >>>
You can see in this example that accessing >>>
In this example, you pass Practicing With Python enumerate()You should use Natural Count of Iterable ItemsIn the previous section, you saw how to use This example is slightly modified from
When one of these items is present, Conditional Statements to Skip ItemsUsing conditional statements to process items can be a very powerful technique. Sometimes you might need to perform an action on only the very first iteration of a loop, as in this example: >>>
In this example, you use a list as a mock database of users. The first user is your testing user, so you want to print extra diagnostic information about that user. Since you’ve set up your system so that the test user is first, you can use the first index value of the loop to print extra verbose output. You can also combine mathematical operations with conditions for the count or index. For instance, you might need to return items from an iterable, but only if they have an even index. You can do this by using >>>
Within the You can make the code more Pythonic by using a list comprehension to do the same thing in one line without initializing the empty list: >>>
In this example code, You can verify that >>>
As expected, >>>
Python strings are sequences, which can be used in loops as well as in integer indexing and slicing. So in the case of strings, you can use square brackets to achieve the same functionality as >>>
Using string slicing here,
you give the starting index However, as you saw earlier, generators and iterators can’t be indexed or sliced, so you’ll still find >>>
In this example, you define You can use generator functions in loops, though, and you do so on the last line by passing Understanding Python enumerate()In the last
few sections, you saw examples of when and how to use To get a better sense of how
One way to write a function meeting these specifications is given in the Python documentation: >>>
For each >>>
First, you create a list of the four seasons to work with. Next, you show that calling
Finally, you create two lists from Although
you can implement an equivalent function for Unpacking Arguments With enumerate()When you use Argument unpacking is the idea that a tuple can be split into several variables depending on the length of the sequence. For instance, you can unpack a tuple of two elements into two variables: >>>
First, you create a tuple with two elements, When you call >>>
In this example, you create a list called Then you use Python’s built-in Calling When an iterable is used in a If an iterable returns a tuple, then you can use argument unpacking to assign the elements of the tuple to multiple variables. This is what you did earlier in this tutorial by using two loop variables. Another time you might have seen argument unpacking with a >>>
By using You can combine >>>
In the There are other ways to emulate the behavior of >>>
Using ConclusionPython’s In this tutorial, you learned how to:
You also saw Watch Now This tutorial has a related video course created by the Real Python team. Watch it together with the written tutorial to deepen your understanding: Looping With Python enumerate() How do I iterate count in Python?With each iteration, Python automatically adds 1 to the value of 'count'. The program keeps iterating as long as the value of 'count' is in the range specified in the loop (in this case as long as 'count' is in the range 0 to 5). Once it reaches the end of the range (5) the iteration stops.
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