ZeroDivisionError: float division by zero tried to resolve but failed

Question

import math
avg_cost = []
for [e,l] in lis:
    length = ZomatoData[(ZomatoData["establishment"]==e) & (ZomatoData["locality"]==l)].shape[0]
    avg_cost.append(math.ceil(ZomatoData[(ZomatoData["establishment"]==e) & (ZomatoData["locality"]==l) & (ZomatoData["average_cost_for_two"]!=0)]["average_cost_for_two"].mean()*length/(length-1)))
avg_cost

---

ZeroDivisionError                         Traceback (most recent call last)
<ipython-input-189-419eb31f025c> in <module>()
      3 for [e,l] in lis:
      4     length = ZomatoData[(ZomatoData["establishment"]==e) & (ZomatoData["locality"]==l)].shape[0]
----> 5     avg_cost.append(math.ceil(ZomatoData[(ZomatoData["establishment"]==e) & (ZomatoData["locality"]==l) & (ZomatoData["average_cost_for_two"]!=0)]["average_cost_for_two"].mean()*length/(length-1)))
      6 avg_cost

ZeroDivisionError: float division by zero

Can anybody help me with this?

Answer 1

Could you not condition your append statement as such:

import math
avg_cost = []
for [e,l] in lis:
    length = ZomatoData[(ZomatoData["establishment"]==e) & (ZomatoData["locality"]==l)].shape[0]
    if length != 1:
        avg_cost.append(math.ceil(ZomatoData[(ZomatoData["establishment"]==e) & (ZomatoData["locality"]==l) & (ZomatoData["average_cost_for_two"]!=0)]["average_cost_for_two"].mean()*length/(length-1)))
avg_cost

Since the "divide by zero" scenario appears to happen if length is equal to "1".