python pandas function object 沒有屬性 min

Question

試圖查找新近度但出現錯誤

AttributeError: 'function' object 沒有屬性 'min'

代碼：

#Generating recency function

# Filtering data for customerid and invoice_date
recency  = order_wise[['CustomerID','InvoiceDate']]

# Finding max data
maximum = max(recency.InvoiceDate)

# Adding one more day to the max data, so that the max date will have 1 as the difference and not zero.
maximum = maximum + pd.DateOffset(days=1)
recency['diff'] = maximum - recency.InvoiceDate
recency.head()

df = pd.DataFrame(recency.groupby('CustomerID').diff.min())
df = df.reset_index()
df.columns = ["CustomerID", "Recency"]
df.head()

Answer 1

pandas DataFrame 有一個diff方法。 要訪問名為'diff'的列，您可以使用：

df = pd.DataFrame(recency.groupby('CustomerID')['diff'].min())

或者，如果您想堅持使用點表示法，您可以為該列指定一個不同的名稱：

recency['Diff'] = maximum - recency.InvoiceDate

df = pd.DataFrame(recency.groupby('CustomerID').Diff.min())