How to remove rows in a dataframe if the cells are empty using python?

Question

I have a dataframe in which I am trying to retrieve data only if certain value exisits in a specific column. If the value in a specific column is empty or None, that particular row should be discarded. Below is the sample dataset:

|   A   |  B  | C |
| ----- | ----|---|
| Test1 | 111 | y | 
| Test2 | 222 | y |
| Test3 | 333 |   |
| Test4 | 444 | y |

If the data is missing in column C then that row should be discarded. The desired output is:

|   A   |  B  | C |
| ----- | ----|---|
| Test1 | 111 | y | 
| Test2 | 222 | y |
| Test4 | 444 | y |

I am trying to achieve this using below snippet but, this produces duplicates also

for x in df["C"]:
    if x == "y":
        for y in df["A"]:
            sample.append(y)

        for z in df["B"]:
            sample_1.append(z)

    else:
        continue

Is it also possible to use df.dropna() in this case?