How to remove lines which start with something in Python?

Question

I need to remove all lines, which start with the letter "C" in the column"InvoiceNo".cI couldn't find an answer here that is why I would appreciate any help.

import numpy as np
import pandas as pd
import csv
from matplotlib import pyplot as plt
import xlsxwriter
import re


dataset = pd.read_excel('OnlineRetail2.xlsx')
dataset.head()

Answer 1

If you could provide some sample data in plain text, it would help me test this, but I believe this should do the trick.

dataset = dataset.loc[dataset.InvoiceNo.str[0] != 'C'].copy()

Basically select those rows where dataset.InvoiceNo does not start with the letter C, and then reassign your dataset to a copy of just those rows (throw everything else out).

Answer 2

You can exclude any line starting with a comment when reading a file in pandas. For excel:

dataset = pd.read_excel('OnlineRetail2.xlsx', comment="C")

Search for 'comment' in the 'read_excel' documentation .

Answer 3

dataset[dataset["InvoiceNo"].str[0] != "C"]