berellevy

Import pandas as pd 
from django.db import models

class QuerySetWithDataFrame(models.QuerySet):
    def df(self, *args, **kwargs):
        return pd.DataFrame.from_records(self, 
                                        *args, 
                                        **kwargs)

# usage:

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remove(data) {
    const findAndRemoveNode = function (startingNode, data) {
      if (startingNode === null) {
        return null;
      }
      if (data === startingNode.data) {
        if (startingNode.left === null && startingNode.right === null) {
          return null;
        }
        if (startingNode.left === null) {

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class Node {
  constructor(data, left = null, right = null) {
    this.data = data;
    this.left = left;
    this.right = right;
  }
}

class BST {
  constructor() {

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    def index
      feed = current_user.feed(params[:page_num].to_i)
      render json: feed
    end

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def feed(page_num)
  page_qty = 5
  offset = page_num * page_qty
  feed = Post.order(updated_at: :desc).where(user_id: followees_ids).limit(page_qty)
             .offset(offset) # I broke the lines up because it gets cut off in medium.com
  View.batch_create(self, feed)
end

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class Cart < ApplicationMethod
  ...
  def make_purchase
    if cart_items.length > 0 
      p = Purchase.create(user: self.user)
      p.cart_items = self.cart_items
      p.save
      return p.display_purchase
    else
      return {error: "No items to purchase"}

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class RemoveCartIdFromCartItems < ActiveRecord::Migration[6.0]
  def change
    remove_column :cart_items, :cart_id
  end
end

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class Cart < ApplicationRecord
  belongs_to :user
  has_many :cart_items, as: :itemable
  ...
end

class Purchase < ApplicationRecord
  belongs_to :user
  has_many :cart_items, as: :itemable
  ...

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class CartItem < ApplicationRecord
  belongs_to :itemable, polymorphic: true
  belongs_to :item
  validates :itemable_type, :itemable_id, presence: true

  ...
  

end

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class AddItemableToCartItems < ActiveRecord::Migration[6.0]
  def change
    add_reference :cart_items, :itemable, polymorphic: true
  end
end