若函数 $f\left(x\right)=\left\{\begin{array}{c}\frac{1}{x},\mathit{\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}\hspace{0.33em}x}<0\\ (\frac{1}{3}{)}^x,\mathit{\hspace{0.33em}x}\ge 0\end{array}\right.$ 则不等式 $\left|f\right(x\left)\right|\ge \frac{1}{3}$的解集为____________。