I have a pandas df with subentries. I would like to make a condition for a particular subentry, and if this condition is not fulfilled, I would like to drop the entire row so I could update the df.

For example, I would like to check each subentry 0 for all the entries and give a condition that if pt<120 then drop the entire entry.

```
               pt
entry subentry
0     0        100
      1        200
      2        300
1     0        200
      1        300
2     0        80
      1        300
      3        400
      4        300
...   ...      ...

```

So, the entry 0 and 2 (with all the subentries) should be deleted.

```
               pt
entry subentry
1     0        200
      1        300
...   ...      ...

```

I tried using:

```
df.loc[(slice(None), 0), :]["pt"]>100

```

but it creates a new series and I cannot pass it to the original df because it does not match the entries/subentries. Thank you.