python之如何用 '\0' 替换 '/0'

为什么像下面这样用前斜杠替换反斜杠对第二个反斜杠不起作用？:

x = 'O:\MAP\04_Operational Finance\Billing\Billings Reconciliation'.replace('\\', '/') 
print(x) 

打印输出为:

O:/MAP_Operational Finance/Billing/Billings Reconciliation