找出给定数据集中各列中缺失值的百分比

时间:2018-06-27 20:33:10

标签: python python-3.x pandas numpy

import pandas as pd
df = pd.read_csv('https://query.data.world/s/Hfu_PsEuD1Z_yJHmGaxWTxvkz7W_b0')
percent= 100*(len(df.loc[:,df.isnull().sum(axis=0)>=1 ].index) / len(df.index))
print(round(percent,2))

输入为https://query.data.world/s/Hfu_PsEuD1Z_yJHmGaxWTxvkz7W_b0

,输出应该是

Ord_id                 0.00
Prod_id                0.00
Ship_id                0.00
Cust_id                0.00
Sales                  0.24
Discount               0.65
Order_Quantity         0.65
Profit                 0.65
Shipping_Cost          0.65
Product_Base_Margin    1.30
dtype: float64

13 个答案:

答案 0 :(得分:11)

这个怎么样?我想我实际上曾经在这里找到过类似的东西,但是现在看不到...

percent_missing = df.isnull().sum() * 100 / len(df)
missing_value_df = pd.DataFrame({'column_name': df.columns,
                                 'percent_missing': percent_missing})

如果要对丢失的百分比进行排序,请按照上述步骤操作:

missing_value_df.sort_values('percent_missing', inplace=True)

如评论中所述,您也许也可以仅通过上面我的代码中的第一行即可:

percent_missing = df.isnull().sum() * 100 / len(df)

答案 1 :(得分:9)

我们将meanisnull一起使用:

df.isnull().mean() * 100

输出:

Ord_id                 0.000000
Prod_id                0.000000
Ship_id                0.000000
Cust_id                0.000000
Sales                  0.238124
Discount               0.654840
Order_Quantity         0.654840
Profit                 0.654840
Shipping_Cost          0.654840
Product_Base_Margin    1.297774
dtype: float64

IIUC:

df.isnull().sum() / df.shape[0] * 100.00

输出:

Ord_id                 0.000000
Prod_id                0.000000
Ship_id                0.000000
Cust_id                0.000000
Sales                  0.238124
Discount               0.654840
Order_Quantity         0.654840
Profit                 0.654840
Shipping_Cost          0.654840
Product_Base_Margin    1.297774
dtype: float64

答案 2 :(得分:4)

涵盖所有 missing 值并四舍五入结果:

((df.isnull() | df.isna()).sum() * 100 / df.index.size).round(2)

输出:

Out[556]: 
Ord_id                 0.00
Prod_id                0.00
Ship_id                0.00
Cust_id                0.00
Sales                  0.24
Discount               0.65
Order_Quantity         0.65
Profit                 0.65
Shipping_Cost          0.65
Product_Base_Margin    1.30
dtype: float64

答案 3 :(得分:4)

单线解决方案

df.isnull().mean().round(4).mul(100).sort_values(ascending=False)

答案 4 :(得分:0)

import numpy as np
import pandas as pd

raw_data = {'first_name': ['Jason', np.nan, 'Tina', 'Jake', 'Amy'], 
        'last_name': ['Miller', np.nan, np.nan, 'Milner', 'Cooze'], 
        'age': [22, np.nan, 23, 24, 25], 
        'sex': ['m', np.nan, 'f', 'm', 'f'], 
        'Test1_Score': [4, np.nan, 0, 0, 0],
        'Test2_Score': [25, np.nan, np.nan, 0, 0]}
results = pd.DataFrame(raw_data, columns = ['first_name', 'last_name', 'age', 'sex', 'Test1_Score', 'Test2_Score'])


results 

  first_name last_name   age  sex  Test1_Score  Test2_Score
0      Jason    Miller  22.0    m          4.0         25.0
1        NaN       NaN   NaN  NaN          NaN          NaN
2       Tina       NaN  23.0    f          0.0          NaN
3       Jake    Milner  24.0    m          0.0          0.0
4        Amy     Cooze  25.0    f          0.0          0.0

您可以使用以下功能,该功能将在Dataframe中提供输出

  • 零值
  • 缺少值
  • 总价值的百分比
  • 总零缺失值
  • 总零缺失值百分比
  • 数据类型

只需复制并粘贴以下函数,然后通过传递您的pandas Dataframe来调用它

def missing_zero_values_table(df):
        zero_val = (df == 0.00).astype(int).sum(axis=0)
        mis_val = df.isnull().sum()
        mis_val_percent = 100 * df.isnull().sum() / len(df)
        mz_table = pd.concat([zero_val, mis_val, mis_val_percent], axis=1)
        mz_table = mz_table.rename(
        columns = {0 : 'Zero Values', 1 : 'Missing Values', 2 : '% of Total Values'})
        mz_table['Total Zero Missing Values'] = mz_table['Zero Values'] + mz_table['Missing Values']
        mz_table['% Total Zero Missing Values'] = 100 * mz_table['Total Zero Missing Values'] / len(df)
        mz_table['Data Type'] = df.dtypes
        mz_table = mz_table[
            mz_table.iloc[:,1] != 0].sort_values(
        '% of Total Values', ascending=False).round(1)
        print ("Your selected dataframe has " + str(df.shape[1]) + " columns and " + str(df.shape[0]) + " Rows.\n"      
            "There are " + str(mz_table.shape[0]) +
              " columns that have missing values.")
#         mz_table.to_excel('D:/sampledata/missing_and_zero_values.xlsx', freeze_panes=(1,0), index = False)
        return mz_table

missing_zero_values_table(results)

输出

Your selected dataframe has 6 columns and 5 Rows.
There are 6 columns that have missing values.

             Zero Values  Missing Values  % of Total Values  Total Zero Missing Values  % Total Zero Missing Values Data Type
last_name              0               2               40.0                          2                         40.0    object
Test2_Score            2               2               40.0                          4                         80.0   float64
first_name             0               1               20.0                          1                         20.0    object
age                    0               1               20.0                          1                         20.0   float64
sex                    0               1               20.0                          1                         20.0    object
Test1_Score            3               1               20.0                          4                         80.0   float64

如果要保持简单,则可以使用以下函数来获取%中的缺失值

def missing(dff):
    print (round((dff.isnull().sum() * 100/ len(dff)),2).sort_values(ascending=False))


missing(results)

Test2_Score    40.0
last_name      40.0
Test1_Score    20.0
sex            20.0
age            20.0
first_name     20.0
dtype: float64

答案 5 :(得分:0)

您正在寻找的解决方案是:

round(df.isnull().mean()*100,2) 

这会将百分比四舍五入到小数点后两位

另一种方法是

round((df.isnull().sum()*100)/len(df),2)

但这并不像使用mean()那样有效。

答案 6 :(得分:0)

如果下面有多个数据框,则该函数可以按百分比计算每列中的缺失值数量

def miss_data(df):
    x = ['column_name','missing_data', 'missing_in_percentage']
    missing_data = pd.DataFrame(columns=x)
    columns = df.columns
    for col in columns:
        icolumn_name = col
        imissing_data = df[col].isnull().sum()
        imissing_in_percentage = (df[col].isnull().sum()/df[col].shape[0])*100

        missing_data.loc[len(missing_data)] = [icolumn_name, imissing_data, imissing_in_percentage]
    print(missing_data) 

答案 7 :(得分:0)

通过以下代码,您可以从每一列中获取相应的百分比值。如果您愿意,只需用df切换名称train_data即可。

输入:

In [1]:

all_data_na = (train_data.isnull().sum() / len(train_data)) * 100
all_data_na = all_data_na.drop(all_data_na[all_data_na == 0].index).sort_values(ascending=False)[:30]
missing_data = pd.DataFrame({'Missing Ratio' :all_data_na})
missing_data.head(20)

输出:

Out[1]: 
                                Missing Ratio
 left_eyebrow_outer_end_x       68.435239
 left_eyebrow_outer_end_y       68.435239
 right_eyebrow_outer_end_y      68.279189
 right_eyebrow_outer_end_x      68.279189
 left_eye_outer_corner_x        67.839410
 left_eye_outer_corner_y        67.839410
 right_eye_inner_corner_x       67.825223
 right_eye_inner_corner_y       67.825223
 right_eye_outer_corner_x       67.825223
 right_eye_outer_corner_y       67.825223
 mouth_left_corner_y            67.811037
 mouth_left_corner_x            67.811037
 left_eyebrow_inner_end_x       67.796851
 left_eyebrow_inner_end_y       67.796851
 right_eyebrow_inner_end_y      67.796851
 mouth_right_corner_x           67.796851
 mouth_right_corner_y           67.796851
 right_eyebrow_inner_end_x      67.796851
 left_eye_inner_corner_x        67.782664
 left_eye_inner_corner_y        67.782664

答案 8 :(得分:0)

对我来说,我是那样做的:

def missing_percent(df):
        # Total missing values
        mis_val = df.isnull().sum()
        
        # Percentage of missing values
        mis_percent = 100 * df.isnull().sum() / len(df)
        
        # Make a table with the results
        mis_table = pd.concat([mis_val, mis_percent], axis=1)
        
        # Rename the columns
        mis_columns = mis_table.rename(
        columns = {0 : 'Missing Values', 1 : 'Percent of Total Values'})
        
        # Sort the table by percentage of missing descending
        mis_columns = mis_columns[
            mis_columns.iloc[:,1] != 0].sort_values(
        'Percent of Total Values', ascending=False).round(2)
        
        # Print some summary information
        print ("Your selected dataframe has " + str(df.shape[1]) + " columns.\n"      
            "There are " + str(mis_columns.shape[0]) +
              " columns that have missing values.")
        
        # Return the dataframe with missing information
        return mis_columns

答案 9 :(得分:0)

让我们分解您的问题

  1. 您想要丢失价值的百分比
  2. 应按升序排序,并将值四舍五入为2个浮点数

说明:

  1. dhr [fill_cols] .isnull()。sum()-按列给出缺失值的总数
  2. dhr.shape [0]-给出总行数
  3. (dhr [fill_cols] .isnull()。sum()/ dhr.shape [0])-为您提供一系列以百分比作为值和以列名称作为索引的
  4. 由于输出是系列,因此您可以根据值进行四舍五入和排序

代码:

(dhr[fill_cols].isnull().sum()/dhr.shape[0]).round(2).sort_values()

参考: sortround

答案 10 :(得分:0)

import numpy as np

import pandas as pd

df = pd.read_csv('https://query.data.world/s/Hfu_PsEuD1Z_yJHmGaxWTxvkz7W_b0')

df.loc[np.isnan(df['Product_Base_Margin']),['Product_Base_Margin']]=df['Product_Base_Margin'].mean()

print(round(100*(df.isnull().sum()/len(df.index)), 2))

答案 11 :(得分:0)

试试这个解决方案


import pandas as pd
df = pd.read_csv('https://query.data.world/s/Hfu_PsEuD1Z_yJHmGaxWTxvkz7W_b0')
print(round(100*(df.isnull().sum()/len(df.index)),2))

答案 12 :(得分:-1)

# Why this chord is not running it shows error 

  File "<tokenize>", line 19
    return mis_val_table_ren_columns
    ^
IndentationError: unindent does not match any outer indentation level
# check number & percentage of missing value in the columns
def missing_values_table(df):
        mis_val = df.isnull().sum() #total missing values
        mis_val_percent = 100 * df.isnull().sum() / len(df) #percentage of missing values
        mis_val_table = pd.concat([mis_val, mis_val_percent], axis=1) #make a table with the results
        mis_val_table_ren_columns = mis_val_table.rename(
        columns = {0 : 'Missing Values', 1 : '% of Total Values'}) #rename the columns
     # sort the table by percentage of missing value
        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 same summary information
        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 the dataframe with missing information
    return mis_val_table_ren_columns

 # missing values statistics
    missing_values = missing_values_table(data_df)
    missing_values.head()