I want to rename rows in python program (version – spyder 3
– python 3.6
) . At this point I have something like that:
import pandas as pd data = pd.read_csv(filepath, delim_whitespace = True, header = None)
Before that i wanted to rename my columns:
data.columns = ['A', 'B', 'C']
It gave me something like that.
A B C 0 1 n 1 1 1 H 0 2 2 He 1 3 3 Be 2
But now, I want to rename rows. I want:
A B C n 1 n 1 H 1 H 0 He 2 He 1 Be 3 Be 2
How can I do it? The main idea is to rename every row created by pd.read
by the data in the B column. I tried something like this:
for rows in data: data.rename(index={0:'df.loc(index, 'B')', 1:'one'})
but it’s not working.
Any ideas? Maybe just replace the data frame rows by column B? How?
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Answer
I think need set_index
with rename_axis
:
df1 = df.set_index('B', drop=False).rename_axis(None)
Solution with rename
and dictionary:
df1 = df.rename(dict(zip(df.index, df['B']))) print (dict(zip(df.index, df['B']))) {0: 'n', 1: 'H', 2: 'He', 3: 'Be'}
If default RangeIndex
solution should be:
df1 = df.rename(dict(enumerate(df['B']))) print (dict(enumerate(df['B']))) {0: 'n', 1: 'H', 2: 'He', 3: 'Be'}
Output:
print (df1) A B C n 1 n 1 H 1 H 0 He 2 He 1 Be 3 Be 2
EDIT:
If dont want column B
solution is with read_csv
by parameter index_col
:
import pandas as pd temp=u"""1 n 1 1 H 0 2 He 1 3 Be 2""" #after testing replace 'pd.compat.StringIO(temp)' to 'filename.csv' df = pd.read_csv(pd.compat.StringIO(temp), delim_whitespace=True, header=None, index_col=[1]) print (df) 0 2 1 n 1 1 H 1 0 He 2 1 Be 3 2