pandas数据清洗删除

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pandas数据清洗删除

ACxz   2022-06-20 我要评论

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_idtypetitledirectorcastcountrydate_addedrelease_yearratingdurationlisted_indescription
0s1MovieDick Johnson Is DeadKirsten JohnsonNaNUnited StatesSeptember 25, 20212020PG-1390 minDocumentariesAs her father nears the end of his life, filmm...
1s2TV ShowBlood & WaterNaNAma Qamata,
Khosi Ngema,
Gail Mabalane,
Thaban...
South AfricaSeptember 24, 20212021TV-MA2 SeasonsInternational TV Shows,
TV Dramas,
TV Mysteries
After crossing paths at a party, a Cape Town t...
2s3TV ShowGanglandsJulien LeclercqSami Bouajila,
Tracy Gotoas,
Samuel Jouy,
Nabi...
NaNSeptember 24, 20212021TV-MA1 SeasonCrime TV Shows,
International TV Shows,
TV Act...
To protect his family from a powerful drug lor...
3s4TV ShowJailbirds New OrleansNaNNaNNaNSeptember 24, 20212021TV-MA1 SeasonDocuseries, Reality TVFeuds, flirtations and toilet talk go down amo...
4s5TV ShowKota FactoryNaNMayur More,
Jitendra Kumar,
Ranjan Raj,
Alam K...
IndiaSeptember 24, 20212021TV-MA2 SeasonsInternational 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
director263429.9
country8319.4
cast8259.4
date_added100.1
rating40.0
duration30.0

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
country8319.4
cast8259.4
date_added100.1
rating40.0
duration30.0

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)

 到此这篇关于pandas数据清洗实现删除的项目实践的文章就介绍到这了,更多相关pandas数据清洗删除内容请搜索以前的文章或继续浏览下面的相关文章希望大家以后多多支持!

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