我想将权重返回到直方图,但名称只出现一次。
df = pd.DataFrame({'Name': ['Bob', 'Simon', 'Bill', 'Mary', 'Mary', 'Bob'],
'Weight': [70, 72, 71, 67, 67, 70]})
此:
Bob 70
Simon 72
Bill 71
Mary 67
使用drop_duplicates
:
out = df.drop_duplicates(['Name', 'Weight'])
print(out)
# Output
Name Weight
0 Bob 70
1 Simon 72
2 Bill 71
3 Mary 67
您需要groupby
:
df.groupby('Name')['Weight'].mean()
如果您只想获取每个名称的第一个可用数据点:
df.groupby('Name')['Weight'].first()
我们可以使用groupby
函数和聚合函数作为mean
数据看起来像这个
>>> df = pd.DataFrame({'Name': ['Bob', 'Simon', 'Bill', 'Mary', 'Mary', 'Bob'], 'Weight': [70, 72, 71, 67, 67, 70]})
>>> print(df)
Name Weight
0 Bob 70
1 Simon 72
2 Bill 71
3 Mary 67
4 Mary 67
5 Bob 70
>>> df2 = df.groupby(['Name']).mean()
>>> print(df2)
Name Weight
0 Bill 71
1 Bob 70
2 Mary 67
3 Simon 72
将Name
索引列转换为列并添加RangeIndex
>>> df2['Name'] = df2.index
>>> df2 = df2[['Name', 'Weight']]
>>> df2.set_index(pd.RangeIndex(start=0, stop=len(df2), step=1), inplace=True)
>>> print(df2)
Name Weight
0 Bill 71
1 Bob 70
2 Mary 67
3 Simon 72
执行以下操作:
df = df.drop_duplicates(subset=['Name', 'Weight'])
print(df)
输出:
>>> Name Weight
0 Bob 70
1 Simon 72
2 Bill 71
3 Mary 67