How can I combine two single-column datasets into a single Pandas data frame?
I would import the datasets in pandas separately, mold them as you please, and then you can use the pd.concat function. This will assume that the instances are aligned by the automatically assigned index in pandas. If there is more data in one list than the other, the missing values will be NaN.

df1 = pd.DataFrame(data=[1,2,3])
df2 = pd.DataFrame(data=['a','b','c','d'])
dfs = pd.concat([df1, df2], axis=1)


If you have an index to link the text to the labels, then you can use the pd.merge function.

df1 = pd.DataFrame(data=[1,2,3])
df2 = pd.DataFrame(data=['a','b','c','d'])
dfs = df1.merge(df2, on='index')