Method createColumns

src/danfojs-base/transformers/merge.ts:139–164

* Generate columns for the newly generated merged DataFrame * e.g df = { * key1: ["KO", "K0", "K3", "K4"], * Key2: ["K1", "K1", "K3", "K5"], * A: [1,2,3,4] * B: [3,4,5,6] * } * df2 = { * key1: ["KO", "K0", "K3", "K4"], * Key2: ["K1", "K1", "K3", "K5"], * A: [1,2,

()

   * number of duplicate of that column
   */
  private createColumns() {
    const self = this
    this.leftCol = self.left.columns.filter((_, index)=>{
      return !self.leftColIndex.includes(index)
    })
    this.rightCol = self.right.columns.filter((_, index) => {
      return !self.rightColIndex.includes(index)
    })
    this.columns = [...this.on]
    const duplicateColumn: {
      [key: string] : number
    } = {}
    const tempColumn = [...this.leftCol]
    tempColumn.push(...this.rightCol)
    for (let i=0; i< tempColumn.length; i++) {
      const col = tempColumn[i] as string
      if (utils.keyInObject(duplicateColumn, col)) {
        let columnName = `${col}_${duplicateColumn[col]}`
        this.columns.push(columnName)
        duplicateColumn[col] +=1
      } else {
        this.columns.push(col)
        duplicateColumn[col] = 1
      }
    } 
  }

  /**
   * The basic methos perform the underneath operation of generating