text_html_output_1.png application_vnd.jupyter.stderr_output_1.png
import pandas as pd # data processing, CSV file I/O (e.g. pd.read_csv)

df = pd.read_csv('../input/goodreadsbooks/books.csv', error_bad_lines=False)

df.rename(columns={'  num_pages': 'num_pages'}, inplace=True)
df.columns

df['publication_year'] = [i.split('/')[2] for i in df['publication_date']]
df['decade'] = [int(i) // 10 * 10 for i in df['publication_year']]
df_lang_year = df.groupby(['decade', 'language_code']).count().reset_index()
df_lang_year