{"id":8866,"date":"2021-10-31T21:33:31","date_gmt":"2021-10-31T20:33:31","guid":{"rendered":"https:\/\/monodes.com\/predaelli\/?p=8866"},"modified":"2021-10-31T21:33:31","modified_gmt":"2021-10-31T20:33:31","slug":"write-clean-python-code-using-pipes","status":"publish","type":"post","link":"https:\/\/monodes.com\/predaelli\/2021\/10\/31\/write-clean-python-code-using-pipes\/","title":{"rendered":"Write Clean Python Code Using Pipes"},"content":{"rendered":"
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Write Clean Python Code Using Pipes<\/a><\/em><\/h1>\n

A Short and Clean Approach to Processing Iterables<\/p><\/blockquote>\n

Now that’s an interesting way of coding!<\/p>\n

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Pipes<\/h1>\n<\/div>\n
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A Short and Clean Approach to Processing Iterables<\/h2>\n
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\"Khuyen<\/div>\n<\/div>\n
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Khuyen Tran<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

4 days ago\u00b7<\/span>5 min read<\/p>\n<\/div>\n

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Motivation<\/h1>\n

map<\/code> and filter<\/code> are two efficient Python methods to work with iterables. However, the code can look messy if you use both map<\/code> and filter<\/code> at the same time.<\/p>\n<\/div>\n<\/div>\n

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Wouldn\u2019t be nice if you can use pipes |<\/code> to apply multiple methods on an iterable like below?<\/p>\n

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The library Pipe allows you to do exactly that.<\/p>\n

What is Pipe?<\/h1>\n

Pipe<\/a><\/mark> is a Python library that enables you to use pipes in Python. A pipe (<\/mark>|<\/code><\/mark>) passes the results of one method to another method.<\/mark><\/p>\n

I like Pipe because <\/span>it makes my code look cleaner when applying multiple methods to a Python iterable. Since Pipe only provides a few methods, it is also very easy to learn Pipe. In this article, I will show you some methods I found the most useful.<\/p>\n

To install Pipe, type:<\/p>\n

pip install pipe<\/span><\/pre>\n
Where \u2014 Filter Elements in an Iterable<\/h1>\n
Similar to SQL, Pipe\u2019s where<\/code> method can also be used to filter elements in an iterable.<\/p>\n
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Select \u2014 Apply a Function to an Iterable<\/h1>\n
The select<\/code> method is similar to the map<\/code> method. select<\/code> applies a method to each element of an iterable.<\/p>\n
In the code below, I use select<\/code> to multiply each element in the list by 2.<\/p>\n
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Now, you might wonder: Why do we need the methods where<\/code> and select<\/code> if they have the same functionalities as map<\/code> and filter<\/code> ?<\/p>\n
It is because you can insert one method after another method using pipes. As a result, using pipes removes nested parentheses and makes the code more readable.<\/p>\n
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Unfold Iterables<\/h1>\n
chain \u2014 Chain a Sequence of Iterables<\/h2>\n
It can be a pain to work with a nested iterable. Luckily, you can use chain<\/code> to chain a sequence of iterables.<\/p>\n
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Even though the iterable is less nested after applying chain<\/code>, we still have a nested list. To deal with a deeply nested list, we can use traverse<\/code> instead.<\/p>\n
traverse \u2014 Recursively Unfold Iterables<\/h2>\n
The traverse<\/code> method can be used to recursively unfold iterables. Thus, you can use this method to turn a deeply nested list into a flat list.<\/p>\n
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Let\u2019s integrate this method with the select<\/code> method to get the values of a dictionary and flatten the list.<\/p>\n
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Pretty cool!<\/p>\n
Group Elements in a List<\/h1>\n
Sometimes, it might be useful to group elements in a list using a certain function. That could be easily done with the groupby<\/code> method.<\/p>\n
To see how this method works, let\u2019s turn a list of numbers into a dictionary that groups numbers based on whether they are even or odd.<\/p>\n<\/div>\n<\/div>\n
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In the code above, we use groupby<\/code> to group numbers into theEven<\/code> group and theOdd<\/code> group. The output after applying this method looks like the below:<\/p>\n
[('Even', <itertools._grouper at 0x7fbea8030550>),\n ('Odd', <itertools._grouper at 0x7fbea80309a0>)]<\/span><\/pre>\n
Next, we use select<\/code> to turn a list of tuples into a list of dictionaries whose keys are the first elements in the tuples and values are the second elements in the tuples.<\/p>\n
[{'Even': [2, 4, 6, 8]}, {'Odd': [1, 3, 5, 7, 9]}]<\/span><\/pre>\n
Cool! To get only the values that are greater than 2, we can add the where<\/code> method inside the select<\/code> method:<\/p>\n<\/div>\n<\/div>\n
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Note that there are no longer 2<\/code> and 1<\/code> in the outputs.<\/p>\n
dedup \u2014 Deduplicate Values Using a Key<\/h1>\n
The dedup<\/code> method removes duplicates in a list.<\/p>\n
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That might not sound interesting since the set<\/code> method can do the same thing. However, this method is more flexible since it enables you to get unique elements using a key.<\/p>\n
For example, you can use this method to get a unique element that is smaller than 5 and another unique element that is larger than or equal to 5.<\/p>\n
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Now, let\u2019s combine this method with select<\/code> and where<\/code> to get the values of a dictionary that has duplicated keys and None<\/code> values.<\/p>\n
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In the code above, we:<\/p>\n