Why does Python's iter on a mapping return iterkeys instead of iteritems
Download this blogpost from https://codegive.com title: understanding python's iter() on a mapping: iterkeys() vs. iteritems() introduction: python offers a convenient way to work with iterable objects, including dictionaries (also known as mappings), using the iter() function. however, when you apply iter() to a dictionary, it returns an iterator over the dictionary's keys, not the key-value pairs (items). in this tutorial, we will explore why python's iter() behaves this way, and we'll also provide code examples to illustrate the concept. the primary reason python's iter() on a mapping returns keys is for historical and performance reasons. this behavior dates back to early versions of python when dictionaries only supported iteration over keys. in older python versions, dictionaries did not have a dedicated items() method to return key-value pairs. the only way to iterate over a dictionary's items was to access the keys with keys() and then fetch the corresponding values using those keys. this was not very efficient, especially when you only needed to iterate over the keys. returning keys by default is also more efficient. when you iterate over the keys, you get an iterator that generates keys one at a time. this is more memory-efficient than creating a separate list of key-value pairs. python's dictionary api has evolved, and it now includes a dedicated items() method that returns an iterable view of key-value pairs. to iterate over key-value pairs, you can use iteritems(). here's how you can use iteritems() to iterate over key-value pairs in a dictionary: let's illustrate the difference between using iter() and iteritems() with code examples. output: python's choice to have iter() return keys by default for dictionaries is rooted in historical reasons and performance considerations. while it may seem counterintuitive at first, it makes sense when you consider python's evolution and the need to maintain efficiency. if you need to work with key-value pairs, you can use iteritems() or the more commonly used item ...
Download this blogpost from https://codegive.com title: understanding python's iter() on a mapping: iterkeys() vs. iteritems() introduction: python offers a convenient way to work with iterable objects, including dictionaries (also known as mappings), using the iter() function. however, when you apply iter() to a dictionary, it returns an iterator over the dictionary's keys, not the key-value pairs (items). in this tutorial, we will explore why python's iter() behaves this way, and we'll also provide code examples to illustrate the concept. the primary reason python's iter() on a mapping returns keys is for historical and performance reasons. this behavior dates back to early versions of python when dictionaries only supported iteration over keys. in older python versions, dictionaries did not have a dedicated items() method to return key-value pairs. the only way to iterate over a dictionary's items was to access the keys with keys() and then fetch the corresponding values using those keys. this was not very efficient, especially when you only needed to iterate over the keys. returning keys by default is also more efficient. when you iterate over the keys, you get an iterator that generates keys one at a time. this is more memory-efficient than creating a separate list of key-value pairs. python's dictionary api has evolved, and it now includes a dedicated items() method that returns an iterable view of key-value pairs. to iterate over key-value pairs, you can use iteritems(). here's how you can use iteritems() to iterate over key-value pairs in a dictionary: let's illustrate the difference between using iter() and iteritems() with code examples. output: python's choice to have iter() return keys by default for dictionaries is rooted in historical reasons and performance considerations. while it may seem counterintuitive at first, it makes sense when you consider python's evolution and the need to maintain efficiency. if you need to work with key-value pairs, you can use iteritems() or the more commonly used item ...