Move column by name to front of table in pandas
Here is my df:
Net Upper Lower Mid Zsore
Answer option
More than once a day 0% 0.22% -0.12% 2 65
Once a day 0% 0.32% -0.19% 3 45
Several times a week 2% 2.45% 1.10% 4 78
Once a week 1% 1.63% -0.40% 6 65
How can I move a column by name ("Mid") to the front of the table, index 0. This is what the result should look like:
Mid Upper Lower Net Zsore
Answer option
More than once a day 2 0.22% -0.12% 0% 65
Once a day 3 0.32% -0.19% 0% 45
Several times a week 4 2.45% 1.10% 2% 78
Once a week 6 1.63% -0.40% 1% 65
My current code moves the column by index using df.columns.tolist() but I'd like to shift it by name.
Answer
We can use ix to reorder by passing a list:
In [27]:
# get a list of columns
cols = list(df)
# move the column to head of list using index, pop and insert
cols.insert(0, cols.pop(cols.index('Mid')))
cols
Out[27]:
['Mid', 'Net', 'Upper', 'Lower', 'Zsore']
In [28]:
# use ix to reorder
df = df.ix[:, cols]
df
Out[28]:
Mid Net Upper Lower Zsore
Answer_option
More_than_once_a_day 2 0% 0.22% -0.12% 65
Once_a_day 3 0% 0.32% -0.19% 45
Several_times_a_week 4 2% 2.45% 1.10% 78
Once_a_week 6 1% 1.63% -0.40% 65
Another method is to take a reference to the column and reinsert it at the front:
In [39]:
mid = df['Mid']
df.drop(labels=['Mid'], axis=1,inplace = True)
df.insert(0, 'Mid', mid)
df
Out[39]:
Mid Net Upper Lower Zsore
Answer_option
More_than_once_a_day 2 0% 0.22% -0.12% 65
Once_a_day 3 0% 0.32% -0.19% 45
Several_times_a_week 4 2% 2.45% 1.10% 78
Once_a_week 6 1% 1.63% -0.40% 65
You can also use loc to achieve the same result as ix will be deprecated in a future version of pandas from 0.20.0 onwards:
df = df.loc[:, cols]