python 中不区分大小写的排序

Question

I have a dataframe with X rows and X columns. I would like to display only a part of the table which is sorted (case-insensitive).

Ie, if I extract only a particular column with their count based on the unique rows say df.ROI.values_count() I get an output that looks like the following:

ABDOMINAL CAVITY 48445
ADRENAL GLAND    18889
Abdominal cavity 18282
Accessory sinus  12088
Adipose tissue    3048
Adrenal gland        5
Name: ROI, dtype: int64

But, I would like my output to be sorted case-insensitively. Like the following:

ABDOMINAL CAVITY 48445
Abdominal cavity 18282
ADRENAL GLAND    18889
Adrenal gland        5
Accessory sinus  12088
Adipose tissue    3048
Name: ROI, dtype: int64

How do I do that?

Answer 1

Use Series.sort_index with parameter key :

s = df.ROI.values_count()

s = s.sort_index(key=lambda x: x.str.lower())
print (s)
ABDOMINAL CAVITY    48445
Abdominal cavity    18282
Accessory sinus     12088
Adipose tissue       3048
ADRENAL GLAND       18889
Adrenal gland           5
Name: ROI, dtype: int64