import boto3
import pandas as pd

def merge_tables_from_s3(path, prefix, run_id):
    ''' Merge all csv files into a single one'''
    # Listing all tables for the given run_id
    table_names = []
    for obj in bucket.objects.filter(Prefix=path):
        table_name = obj.key.split('/')[-1]
        prefix_run_id = "{}_{}".format(prefix, run_id)
        if table_name.startswith(prefix_run_id):
            table_names.append(table_name)
    # Merging all of them in a single dataframe
    merged_df = pd.DataFrame() 
    for table_name in table_names:
        obj = bucket.Object(f'{path}/{table_name}')
        table_data = pd.read_csv(obj.get()['Body'])
        merged_df = pd.concat([merged_df,table_data])
    return merged_df