Method substr

src/danfojs-base/core/strings.ts:608–626

(startIndex = 0, num = 1, options?: { inplace?: boolean })

    */
    substr(startIndex: number, num: number, options?: { inplace?: boolean }): Series
    substr(startIndex = 0, num = 1, options?: { inplace?: boolean }): Series | void {
        const { inplace } = { inplace: false, ...options }
        const newArr: Array<string | number> = [];
        this.values.map((val) => {
            if (utils.isEmpty(val)) {
                newArr.push(NaN);
            } else {
                newArr.push(`${String(val).substr(startIndex, num)}`);
            }
        });
        if (inplace) {
            this.series.$setValues(newArr as ArrayType1D)
            this.series.print()
        } else {
            const sf = this.series.copy()
            sf.$setValues(newArr as ArrayType1D)
            return sf;
        }
    }

    /**
    * Extracts the characters from a string, between two specified indices