My current code is shown below - I'm importing a MAT file and trying to create a DataFrame from variables within it:

```
mat = loadmat(file_path)  # load mat-file
Variables = mat.keys()    # identify variable names

df = pd.DataFrame         # Initialise DataFrame

for name in Variables:

    B = mat[name]
    s = pd.Series (B[:,1])

```

So within the loop, I can create a series of each variable (they're arrays with two columns - so the values I need are in column 2)

My question is how do I append the series to the dataframe? I've looked through the documentation and none of the examples seem to fit what I'm trying to do.