Python Repeat N Times

Python Repeat Loop N Times
Python Repeat N Times Char
Python Repeat List N Times
Python Repeat Value N Times
Python Repeat Character N Times

In this post, you will learn how to use loops in Python. Loops are a commonly used structure in programming that allows you to repeat a block of code a set number of times, or until you meet a. A for loop in Python is a statement that helps you iterate a list, tuple, string, or any kind of sequence. Essentially, the for loop is only used over a sequence and its use-cases will vary depending on what you want to achieve in your program. » Become a Python Wizard for $50 with the Complete Python Certification Bundle! In this post, you will learn how to use loops in Python. Loops are a commonly used structure in programming that.

A Twitter friend proposed an idiom for doing something N times in Python I hadn’t seen before, Using itertools.repeat instead of range. I was curious if it was better.

So huh, itertools.repeat is about 50% the cost of using range. We’re only talking 13ns per iteration, or roughly 50 CPU cycles. If you’re doing meaningful work in that loop it won’t matter. Still it’s neat that itertools.repeat is more efficient. Perhaps this shouldn’t surprise me, it doesn’t have to do the work of generating increasing integers. But I’d assumed no one had optimized itertools this carefully.

Note that in Python3 range is an actual type and doesn’t create a list, tuple, iterator, or generator. Also interesting that repeating an integer is 3% more efficient than repeating None; that’s a reproducible result.

Python2 is faster across the board. I see that a lot in Python and it makes me wonder. But the itertools vs. range/xrange difference is still about 50%, or meaningful.

Having now understood all this I’ll go right back to using range() like my grandpappy did.

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Python Repeat Loop N Times

/ Python / Python for loop Repeat

A for loop is used to iterate over a list or sequence of items. In python, we can use for loop ot iterate over a list, a tuple, a dictionary, a set, or a string.

Generally, a for loop is used to repeat a code N number of times, where N is the number of items in the sequence.

1. Syntax of `for` Loop

The variable val represents a value from the sequence, for the current iteration. After each iteration. the value points to next available value in the sequence.

Once, all the values have been iterated, the for loop terminates.

Python supports the nested for loop as well. A nested for loop is one for loop inside another for loop.

2. Python `for` loop examples

2.1. Iterating over list

Python program to iterate over a list of items using for loop. This program prints all the names stored in the list.

Program output.

2.2. Iterating over String

Python program to iterate over a string using for loop.

In Python, strings are iterable. They are a sequence of characters.

Program output.

2.3. Iterate through dictionary

Python program to iterate over a tuples using for loop.

Program output.

2.4. Iterating over set

Python program to iterate over a set using for loop.

Program output.

3. The `break` and `continue` statements

The break statement is used to stop the iteration, and exit the for loop, when a certain condition is met:

Program output.

The continue statement is used to stop the current iteration, and jump to the next iteration in the loop. It does not terminate the for loop.

The break statement is used to stop the iteration, and exit the for loop, when a certain condition is met:

Program output.

4. `for` loop with `else`

The for loop can have an optional else block as well. It is called for...else statement.

The else block in a for...else is executed differently depending on the present of break statement.

If the break statement NOT is present in for loop then else block is executed when all the items in the list have been iterated; and no item is left for iteration.
Program output.
If the break statement is present in for loop:
– The else block will be executed if break has not been executed because the condition for break is not not met.
Program output.
– The else block will NOT be executed if break has not been executed.
Program output.

5. Looping with range() function

In Python, the for loop can be used with range() function as well. The range() generates a sequence of value starting with 0, by default.

For example, range(10) will generate numbers from 0 to 9 (10 numbers).

To generate a custom range of values, we can pass the range parameters in function range(start, stop, step_size).