Method append

src/danfojs-base/core/frame.ts:3134–3214

(
        newValues: ArrayType1D | ArrayType2D | Series | DataFrame,
        index: Array<number | string> | number | string,
        options?: {
            inplace?: boolean,
        }
    )

        }
    ): DataFrame
    append(
        newValues: ArrayType1D | ArrayType2D | Series | DataFrame,
        index: Array<number | string> | number | string,
        options?: {
            inplace?: boolean,
        }
    ): DataFrame | void {
        const { inplace } = { inplace: false, ...options }

        if (!newValues) {
            throw Error(`ParamError: newValues must be a Series, DataFrame or Array`);
        }

        if (!index) {
            throw Error(`ParamError: index must be specified`);
        }

        let rowsToAdd = []
        if (newValues instanceof Series) {

            if (newValues.values.length !== this.shape[1]) {
                throw Error(`ValueError: length of newValues must be the same as the number of columns.`);
            }
            rowsToAdd = [newValues.values]

        } else if (newValues instanceof DataFrame) {

            if (newValues.shape[1] !== this.shape[1]) {
                throw Error(`ValueError: length of newValues must be the same as the number of columns.`);
            }
            rowsToAdd = newValues.values

        } else if (Array.isArray(newValues)) {

            if (utils.is1DArray(newValues)) {
                rowsToAdd = [newValues]
            } else {
                rowsToAdd = newValues
            }

            if ((rowsToAdd[0] as any).length !== this.shape[1]) {
                throw Error(`ValueError: length of newValues must be the same as the number of columns.`);
            }

        } else {
            throw Error(`ValueError: newValues must be a Series, DataFrame or Array`);
        }


        let indexInArrFormat: Array<number | string> = []
        if (!Array.isArray(index)) {
            indexInArrFormat = [index]
        } else {
            indexInArrFormat = index
        }

        if (rowsToAdd.length !== indexInArrFormat.length) {
            throw Error(`ParamError: index must contain the same number of values as newValues`);