Question

如何将两列合并为一个（最终输出）（python / sqlite）

import sqlite3
import pandas as pd

# load data
df = pd.read_csv('CurriculumAuditReport.csv')

# strip whitespace from headers
df.columns = df.columns.str.strip()

con = sqlite3.connect("sans.db")

# drop data into database
df.to_sql("MyTable", con, if_exists='replace')

qry = """
SELECT department, count(*) as cnt
FROM MyTable
WHERE CompletedTraining = 'Incomplete'
GROUP BY department
"""

qry2 = """
SELECT [Employee Name], Department, [Date Assigned] FROM MyTable Where CompletedTraining ='Incomplete' ORDER BY Department ASC
"""


df = pd.read_sql_query(qry, con)
df2 = pd.read_sql_query(qry2, con)

print(df.to_json())
print(df2)


con.close()

我可以将部门与cnt合并吗？所以我有AQPSD：6，ASD：8，CO：2等???

目前：预计有2列

   Department  count(*)

0       AQPSD         6
1         ASD         8
2          CO         2
3       ECARS         3
4          ED         6
5          EO         4
6         ISD         4
7        MSCD         5
8         OIS         1
9          RD         2
10        TTD         4

这有以下输出：1列（难以显示的那种但是我的最终目标）

Department

0       AQPSD 6
1         ASD 8
2          CO 2
3       ECARS 3
4          ED 6
5          EO 4
6         ISD 4
7        MSCD 5
8         OIS 1
9          RD 2
10        TTD 4

Answer 1

您可以在SQLite端或Pandas中执行此操作。

选项1（使用SQLite）：

qry = """
SELECT department || ' ' || cast(count(*) as text) as col_name
FROM MyTable
WHERE CompletedTraining = 'Incomplete'
GROUP BY department
"""
df = pd.read_sql(qry, con)

选项2（使用Pandas）：

假设我们有以下DataFrame：

In [79]: df
Out[79]:
   department  cnt
0       AQPSD    6
1         ASD    8
2          CO    2
3       ECARS    3
4          ED    6
5          EO    4
6         ISD    4
7        MSCD    5
8         OIS    1
9          RD    2
10        TTD    4

让我们将其转换为单列DF：

In [80]: df['department'] = df['department'] + ' ' + df.pop('cnt').astype(str)

In [81]: df
Out[81]:
   department
0     AQPSD 6
1       ASD 8
2        CO 2
3     ECARS 3
4        ED 6
5        EO 4
6       ISD 4
7      MSCD 5
8       OIS 1
9        RD 2
10      TTD 4

PS这可以在不使用SQLite的情况下轻松完成，但我们需要一个原始格式的小型可重现样本数据集（可以从CurriculumAuditReport.csv重现数据）

Answer 2

这是一步一步的解决方案：

添加新列并将count列转换为带有＆＃34; astype（str）

的字符串

df['new_column'] = df['Department'] + " " + df['count'].astype(str)

删除您不需要的列

del df['Department']
del df['count']

重命名new_column

df.rename(columns={'new_column': 'Department'}, inplace=True)

我知道它有很多步骤，但有时最好通过小步骤将其分解以便更好地理解。

如何将两列合并为一个（最终输出）（python / sqlite）

2 个答案: