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Mastering flat_map in Python with List Comprehension

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Introduction In Python, when working with nested lists or iterables, one common challenge is flattening them into a single list while applying transformations. Many programming languages provide a built-in flatMap function, but Python does not have an explicit flat_map method. However, Python’s powerful list comprehensions offer an elegant way to achieve the same functionality. This article examines implementation behavior using Python’s list comprehensions and other methods. What is flat_map ? Functional programming  flatMap is a combination of map and flatten . It transforms the collection's element and flattens the resulting nested structure into a single sequence. For example, given a list of lists, flat_map applies a function to each sublist and returns a single flattened list. Example in a Functional Programming Language: List(List(1, 2), List(3, 4)).flatMap(x => x.map(_ * 2)) // Output: List(2, 4, 6, 8) Implementing flat_map in Python Using List Comprehension Python’...

The best helpful hdfs file system commands (3 of 4)

dus-

hadoop fs -dus PATH

dus reports the sum of the file sizes in aggregate rather than individually.

expunge-

hadoop fs -expunge

Empties the trash. If the trash feature is enabled, when a file is deleted, it is first moved into the temporary Trash/folder. The file will be permanently deleted from the Trash/folder only after user-configurable delay.

get -

hadoop -fs -get [-ignorecrc] [-crc] SRC
LOCASDST

Copies files to the local file system.

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