[英]Pandas Dataframe - Conditional Column Creation
我正在嘗試基於另一列的條件邏輯創建一個新列。 我嘗試過搜索,卻找不到能解決我問題的任何內容。
我已經將CSV導入到pandas數據幀中,它的結構如下。 我編輯了這篇文章的一些描述,但除此之外一切都是一樣的:
#code used to load dataframe:
df = pd.read_csv(r"C:\filepath\filename.csv")
#output from print(type(df)):
#class 'pandas.core.frame.DataFrame'
#output from print(df.columns.values):
#['Type' 'Trans Date' 'Post Date' 'Description' 'Amount']
#output from print(df.columns):
Index(['Type', 'Trans Date', 'Post Date', 'Description', 'Amount'], dtype='object')
#output from print
Type Trans Date Post Date Description Amount
0 Sale 01/25/2018 01/25/2018 DESC1 -13.95
1 Sale 01/25/2018 01/26/2018 AMAZON MKTPLACE PMTS -6.99
2 Sale 01/24/2018 01/25/2018 SUMMIT BISTRO -5.85
3 Sale 01/24/2018 01/25/2018 DESC3 -9.13
4 Sale 01/24/2018 01/26/2018 DYNAMIC VENDING INC -1.60
然后我寫下面的代碼:
def criteria(row):
if row.Description.find('SUMMIT BISTRO')>0:
return 'Lunch'
elif row.Description.find('AMAZON MKTPLACE PMTS')>0:
return 'Amazon'
elif row.Description.find('Aldi')>0:
return 'Groceries'
else:
return 'NotWorking'
df['Category'] = df.apply(criteria, axis=0)
錯誤:
Traceback (most recent call last):
File "C:\Users\Test_BankReconcile2.py", line 44, in <module>
df['Category'] = df.apply(criteria, axis=0)
File "C:\Users\Anaconda3\lib\site-packages\pandas\core\frame.py", line 4262, in apply
ignore_failures=ignore_failures)
File "C:\Users\Anaconda3\lib\site-packages\pandas\core\frame.py", line 4358, in _apply_standard
results[i] = func(v)
File "C:\Users\OneDrive\Documents\finance\Test_BankReconcile2.py", line 35, in criteria
if row.Description.find('SUMMIT BISTRO')>0:
File "C:\Users\Anaconda3\lib\site-packages\pandas\core\generic.py", line 3081, in __getattr__
return object.__getattribute__(self, name)
AttributeError: ("'Series' object has no attribute 'Description'", 'occurred at index Type')
我能夠在一個來自不同銀行的非常相似的csv文件上成功執行同樣的命令(這個例子來自我的信用卡),所以我不知道發生了什么,但我可能需要定義數據幀在某種程度上,我不是在做什么? 或者可能是我沒有看到的其他非常明顯的東西? 提前謝謝大家幫我解決這個問題。
是的,您的問題是您需要將axis=1
傳遞給.apply
:
In [52]: df
Out[52]:
Type Trans Date Post Date Description Amount
0 Sale 01/25/2018 01/25/2018 DESC1 -13.95
1 Sale 01/25/2018 01/26/2018 AMAZON MKTPLACE PMTS -6.99
2 Sale 01/24/2018 01/25/2018 SUMMIT BISTRO -5.85
3 Sale 01/24/2018 01/25/2018 DESC3 -9.13
4 Sale 01/24/2018 01/26/2018 DYNAMIC VENDING INC -1.60
In [53]: def criteria(row):
...: if row.Description.find('SUMMIT BISTRO')>0:
...: return 'Lunch'
...: elif row.Description.find('AMAZON MKTPLACE PMTS')>0:
...: return 'Amazon'
...: elif row.Description.find('Aldi')>0:
...: return 'Groceries'
...: else:
...: return 'NotWorking'
...:
In [54]: df.apply(criteria, axis=1)
Out[54]:
0 NotWorking
1 NotWorking
2 NotWorking
3 NotWorking
4 NotWorking
dtype: object
第二個問題是你有一個邏輯錯誤,而不是.find(x) > 0
你想要.find(x) >= 0
,或者更好的是some_string in some_other_string
有關更一般的解決方案,請在循環中省略Description
,而是使用df['Description'].apply(criteria)
與Series.apply
。
同樣在列使用支票子in
。
def criteria(row):
if 'SUMMIT BISTRO' in row:
return 'Lunch'
elif 'AMAZON MKTPLACE PMTS' in row:
return 'Amazon'
elif 'Aldi' in row:
return 'Groceries'
else:
return 'NotWorking'
df['Category'] = df['Description'].apply(criteria)
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