Method append

src/danfojs-base/core/series.ts:1855–1919

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

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

        if (!newValue && typeof newValue !== "boolean" && typeof newValue !== "number") {
            throw Error("Param Error: newValue cannot be null or undefined");
        }

        if (!index) {
            throw Error("Param Error: index cannot be null or undefined");
        }

        const newData = [...this.values]
        const newIndx = [...this.index]

        if (Array.isArray(newValue) && Array.isArray(index)) {

            if (newValue.length !== index.length) {
                throw Error("Param Error: Length of new values and index must be the same");
            }

            newValue.forEach((el, i) => {
                newData.push(el);
                newIndx.push(index[i]);
            });

        } else if (newValue instanceof Series) {
            const _value = newValue.values;

            if (!Array.isArray(index)) {
                throw Error("Param Error: index must be an array");
            }

            if (index.length !== _value.length) {
                throw Error("Param Error: Length of new values and index must be the same");
            }

            _value.forEach((el, i) => {
                newData.push(el);
                newIndx.push(index[i]);
            });
        } else {
            newData.push(newValue);
            newIndx.push(index as string | number);
        }

        if (inplace) {
            this.$setValues(newData as ArrayType1D, false)
            this.$setIndex(newIndx)
        } else {
            const sf = new Series(
                newData,
                {
                    index: newIndx,
                    columns: this.columns,