pandas统计重复值次数的方法实现

from pandas import DataFrame

df = DataFrame({'key1':['a','a','b','b','a','a'],
        'key2':['one','two','one','two','one','one'],
        'data1':[1,2,3,2,1,1],
        # 'data2':np.random.randn(5)
        })
# 打印数据框
print(df)
#  data1 key1 key2
# 0   1  a one
# 1   2  a two
# 2   3  b one
# 3   2  b two
# 4   1  a one
# 5   1  a one

# 重复项
print(df[df.duplicated()])
#  data1 key1 key2
# 4   1  a one
# 5   1  a one

# 统计重复值
dup=df[df.duplicated()].count()
print(dup) # 最后两项重复
# data1  2
# key1   2
# key2   2

# 去除重复项
nodup=df[-df.duplicated()]
print(nodup)
#  data1 key1 key2
# 0   1  a one
# 1   2  a two
# 2   3  b one
# 3   2  b two

count = 0
for i in users_info['user_id'].duplicated():
  if i == True:
    count = count + 1
count

users_info.shape[0] - users_info.drop_duplicates(['user_id']).shape[0]