Flask is a "microframework", it doesn't include database integrations nor many of the things that come by default in Django.

This simplicity and flexibility allow doing things like using NoSQL databases as the main data storage system.

As it is very simple, it's relatively intuitive to learn, although the documentation gets somewhat technical at some points.

// Copyright (c) 2015-2022 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

    /** The key of the message: The target file does not exist in the storage. */
    public static final String ERRORS_storage_file_not_found = "{errors.storage_file_not_found}";

    /** The key of the message: Failed to download {0}. */
    public static final String ERRORS_storage_file_download_failure = "{errors.storage_file_download_failure}";

    /** The key of the message: Storage Access Error: {0} */

	curr fileWriter // Writer for current file entry
	hdr  Header     // Shallow copy of Header that is safe for mutations
	blk  block      // Buffer to use as temporary local storage

	// err is a persistent error.
	// It is only the responsibility of every exported method of Writer to
	// ensure that this error is sticky.
	err error
}

// NewWriter creates a new Writer writing to w.

      }
    }
    return true;
  }

  /**
   * Each instance of MinMaxPriorityQueue encapsulates two instances of Heap: a min-heap and a
   * max-heap. Conceptually, these might each have their own array for storage, but for efficiency's
   * sake they are stored interleaved on alternate heap levels in the same array (MMPQ.queue).
   */
  @WeakOuter
  private final class Heap {
    final Ordering<E> ordering;

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful

stcgroup

// stockholm : Stockholms kommun
// https://www.iana.org/domains/root/db/stockholm.html
stockholm

// storage : XYZ.COM LLC
// https://www.iana.org/domains/root/db/storage.html
storage

// store : Radix Technologies Inc.
// https://www.iana.org/domains/root/db/store.html
store

// stream : dot Stream Limited

collective works based on the Library.

In addition, mere aggregation of another work not based on the Library
with the Library (or with a work based on the Library) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.

  3. You may opt to apply the terms of the ordinary GNU General Public

    /** The key of the message: Plugin */
    public static final String LABELS_menu_plugin = "{labels.menu_plugin}";

    /** The key of the message: Storage */
    public static final String LABELS_menu_storage = "{labels.menu_storage}";

    /** The key of the message: Menu */
    public static final String LABELS_SIDEBAR_MENU = "{labels.sidebar.menu}";

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful