目录
- 准备工作（导入库、导入数据）
- 检测数据情况
- DataFrame.drop(labels=None,axis=0, index=None, columns=None, inplace=False)
- 方式一：删除指定行或列
- 方式二：利用boolean删除满足条件元素所在的行
准备工作（导入库、导入数据）
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
import seaborn as sns
sns.set_style("darkgrid") list_csv = ['Amazon_top_selling_book.csv','breast_cancer_wisconsin.csv','diamonds.csv','insurance.csv','netflix_titles.csv','penguins.csv',
'titanic.csv','winequality-red.csv']
dic_path = r'C:\Users\pandas\Desktop\task\228datasets\datasets'
part_data = pd.read_csv(dic_path+'\\'+list_csv[4])
part_data
| |
show_id |
type |
title |
director |
cast |
country |
date_added |
release_year |
rating |
duration |
listed_in |
description |
| 0 |
s1 |
Movie |
Dick Johnson Is Dead |
Kirsten Johnson |
NaN |
United States |
September 25, 2021 |
2020 |
PG-13 |
90 min |
Documentaries |
As her father nears the end of his life, filmm... |
| 1 |
s2 |
TV Show |
Blood & Water |
NaN |
Ama Qamata,
Khosi Ngema,
Gail Mabalane,
Thaban... |
South Africa |
September 24, 2021 |
2021 |
TV-MA |
2 Seasons |
International TV Shows,
TV Dramas,
TV Mysteries |
After crossing paths at a party, a Cape Town t... |
| 2 |
s3 |
TV Show |
Ganglands |
Julien Leclercq |
Sami Bouajila,
Tracy Gotoas,
Samuel Jouy,
Nabi... |
NaN |
September 24, 2021 |
2021 |
TV-MA |
1 Season |
Crime TV Shows,
International TV Shows,
TV Act... |
To protect his family from a powerful drug lor... |
| 3 |
s4 |
TV Show |
Jailbirds New Orleans |
NaN |
NaN |
NaN |
September 24, 2021 |
2021 |
TV-MA |
1 Season |
Docuseries, Reality TV |
Feuds, flirtations and toilet talk go down amo... |
| 4 |
s5 |
TV Show |
Kota Factory |
NaN |
Mayur More,
Jitendra Kumar,
Ranjan Raj,
Alam K... |
India |
September 24, 2021 |
2021 |
TV-MA |
2 Seasons |
International TV Shows,
Romantic TV Shows,
TV ... |
In a city of coaching centers known to train I... |
| ... |
... |
... |
... |
... |
... |
... |
... |
... |
... |
... |
... |
... |
8807 rows × 12 columns
检测数据情况
Hint:该函数用于检测任意DataFrame中缺失值情况
def missing_values_table(df):
mis_val = df.isnull().sum()
mis_val_percent = 100 * df.isnull().sum() / len(df)
mis_val_table = pd.concat([mis_val, mis_val_percent], axis=1)
mis_val_table_ren_columns = mis_val_table.rename(
columns = {0 : 'Missing Values', 1 : '% of Total Values'})
mis_val_table_ren_columns = mis_val_table_ren_columns[
mis_val_table_ren_columns.iloc[:,1] != 0].sort_values(
'% of Total Values', ascending=False).round(1)
print ("Your selected dataframe has " + str(df.shape[1]) + " columns.\n"
"There are " + str(mis_val_table_ren_columns.shape[0]) +
" columns that have missing values.")
return mis_val_table_ren_columns
missing_values_table(part_data)
Your selected dataframe has 12 columns.
There are 6 columns that have missing values.
| |
Missing Values |
% of Total Values |
| director |
2634 |
29.9 |
| country |
831 |
9.4 |
| cast |
825 |
9.4 |
| date_added |
10 |
0.1 |
| rating |
4 |
0.0 |
| duration |
3 |
0.0 |
DataFrame.drop(labels=None,axis=0, index=None, columns=None, inplace=False)
参数说明：
- labels 就是要删除的行列的名字，用列表给定
- axis 默认为0，指删除行，因此删除columns时要指定axis=1；
- index 直接指定要删除的行
- columns 直接指定要删除的列
- inplace=False，默认该删除操作不改变原数据，而是返回一个执行删除操作后的新dataframe；
- inplace=True，则会直接在原数据上进行删除操作，删除后无法返回。
方式一：删除指定行或列
labels+axis
demo = part_data.drop(['director'], axis=1)
missing_values_table(demo)
Your selected dataframe has 11 columns.
There are 5 columns that have missing values.
| |
Missing Values |
% of Total Values |
| country |
831 |
9.4 |
| cast |
825 |
9.4 |
| date_added |
10 |
0.1 |
| rating |
4 |
0.0 |
| duration |
3 |
0.0 |
方式二：利用boolean删除满足条件元素所在的行
df = df.drop(df[].index)
# 删除release_year年份在2009年之前的行
demo = part_data.drop(part_data[part_data["release_year"]<2009].index)
demo.shape
(7624, 12)
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