绘制时出现条形边框错误

Question

我尝试通过添加edgecolor和linewidth来避免边界错误，但是仍然要面对。

plt.figure(figsize=(20,9), edgecolor="black", linewidth=3 )
loans[loans['credit.policy']==1]['fico'].hist(alpha=0.5,color='blue',
                                              bins=30,label='Credit.Policy=1')
loans[loans['credit.policy']==0]['fico'].hist(alpha=0.5,color='red',
                                              bins=30,label='Credit.Policy=0')
plt.legend()
plt.xlabel('FICO')