import numpy as np
import pandas as pd
from pandas import Series, DataFrame

df = pd.read_csv('./demo_duplicate.csv')
print(df)
print(df['Seqno'].unique()) # [0. 1.]

# 使用duplicated 查看 重复值
# 参数 keep 可以标记重复值 {'first'，'last'，False}
print(df['Seqno'].duplicated())
'''
0  False
1   True
2   True
3   True
4  False
Name: Seqno, dtype: bool
'''

# 删除 series 重复数据
print(df['Seqno'].drop_duplicates())
'''
0  0.0
4  1.0
Name: Seqno, dtype: float64
'''

# 删除 dataframe 重复数据
print(df.drop_duplicates(['Seqno'])) # 按照 Seqno 来 去重
'''
  Price Seqno Symbol    time
0 1623.0  0.0  APPL 1473411962
4 1649.0  1.0  APPL 1473411963
'''
# drop_dujplicates() 第二个参数 keep 包含的值 有： first、last、False
print(df.drop_duplicates(['Seqno'], keep='last')) # 保存最后一个
'''
  Price Seqno Symbol    time
3 1623.0  0.0  APPL 1473411963
4 1649.0  1.0  APPL 1473411963
'''

DataFrame.drop_duplicates（subset = None，keep ='first'，inplace = False ）