I’m trying to find the sum of the variable "candle" in the code below, but not sure how to write the code. I know someone is going to suggest using NumPy, but I don’t even know where to begin with that.

```
for index, row in df.iterrows():
openPrice = row['open']
closePrice = row['close']
if closePrice - openPrice >= 0:
candle = 0
elif closePrice - openPrice <= 0:
candle = 1
```

I’m looping through a dataframe that contains stock prices (open and close). I want to find the difference between the two and find the sum of the times the output is =1. Let’s say the rows are: 1, 0, 0, 1. The sum should be 2.

### >Solution :

Consider following dataframe:

```
open close
0 20 10
1 20 30
2 20 30
3 20 5
```

Then you can do:

```
df["col3"] = (df["close"] - df["open"] < 0).astype(int)
final_sum = df["col3"].sum()
print(df)
print(f"{final_sum=}")
```

This prints:

```
open close col3
0 20 10 1
1 20 30 0
2 20 30 0
3 20 5 1
final_sum=2
```