pip install pandas pip install xlrd
大量記錄的時候，用EXCEL排序處理比較費勁，EXCEL程序動不動就無響應了，用pands完美解決。
# We will use data structures and data analysis tools provided in Pandas library
import pandas as pd
# Import retail sales data from an Excel Workbook into a data frame
# path = '/Documents/analysis/python/examples/2015sales.xlsx'
path = 'F:/python/an.xlsx'
xlsx = pd.ExcelFile(path)
df = pd.read_excel(xlsx, 'Sheet1')
# Let's add a new boolean column to our dataframe that will identify a duplicated order line item (False=Not a duplicate; True=Duplicate)
df['is_duplicated'] = df.duplicated(['ip'])
# We can sum on a boolean column to get a count of duplicate order line items
# df['is_duplicated'].sum()
# Get the records of duplicated, If you need non-dup just use False instead
df_dup = df.loc[df['is_duplicated'] == True]
# Finally let's save our cleaned up data to a csv file
df_dup.to_csv('dup.csv', encoding='utf-8')
ref:https://33sticks.com/python-for-business-identifying-duplicate-data/
