String problem / Select all values > 8000 in pandas dataframe
You can see value of df.dtypes to see what is the type of each column. Then, if the column type is not as you want to, you can change it by df['GM'].astype(float), and then new_df = df.loc[df['GM'].astype(float) > 8000] should work as you want to.
I want to select all values bigger than 8000 within a pandas dataframe. 
new_df = df.loc[df['GM'] > 8000]
However, it is not working. I think the problem is, that the value comes from an Excel file and the number is interpreted as string e.g. "1.111,52". Do you know how I can convert such a string to float / int in order to compare it properly?