It’s elegant in its simplicity and eminently versatile. They can all be the target of a for loop, and the syntax is the same across the board. You will discover more about all the above throughout this series.
FOR LOOP PYTHON GENERATOR
Python features a construct called a generator that allows you to create your own iterator in a simple, straightforward way. User-defined objects created with Python’s object-oriented capability can be made to be iterable. There is a Standard Library module called itertools containing many functions that return iterables.
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![for loop python for loop python](https://technicalblog.in/wp-content/uploads/2020/11/python-loops-3.jpg)
Many built-in and library objects are iterable. Python treats looping over all iterables in exactly this way, and in Python, iterables and iterators abound: Perhaps this seems like a lot of unnecessary monkey business, but the benefit is substantial. This sequence of events is summarized in the following diagram: Schematic Diagram of a Python for Loop
![for loop python for loop python](https://i.ytimg.com/vi/0uJbooxtdEo/maxresdefault.jpg)
The loop body is executed once for each item next() returns, with loop variable i set to the given item for each iteration.
FOR LOOP PYTHON HOW TO
Okay, now you know what it means for an object to be iterable, and you know how to use iter() to obtain an iterator from it. (You will find out how that is done in the upcoming article on object-oriented programming.) Iterators Even user-defined objects can be designed in such a way that they can be iterated over. In fact, almost any object in Python can be made iterable. As you will see soon in the tutorial on file I/O, iterating over an open file object reads data from the file. For example, open files in Python are iterable. Many objects that are built into Python or defined in modules are designed to be iterable. These include the string, list, tuple, dict, set, and frozenset types.īut these are by no means the only types that you can iterate over. > iter ( 42 ) # Integer Traceback (most recent call last):įile "", line 1, in iter ( 42 ) TypeError: 'int' object is not iterable > iter ( 3.1 ) # Float Traceback (most recent call last):įile "", line 1, in iter ( 3.1 ) TypeError: 'float' object is not iterable > iter ( len ) # Built-in function Traceback (most recent call last):įile "", line 1, in iter ( len ) TypeError: 'builtin_function_or_method' object is not iterableĪll the data types you have encountered so far that are collection or container types are iterable. Then you will learn about iterables and iterators, two concepts that form the basis of definite iteration in Python.įinally, you’ll tie it all together and learn about Python’s for loops. You’ll start with a comparison of some different paradigms used by programming languages to implement definite iteration. Here’s what you’ll cover in this tutorial:
FOR LOOP PYTHON CODE
Indefinite iteration, in which the code block executes until some condition is met.
![for loop python for loop python](https://i.ytimg.com/vi/rJhmLQ7JxPM/maxresdefault.jpg)