I have the following dataframe
0
0 0.164560
1 0.000000
2 0.350000
3 0.700000
...
3778 0.350000
3779 0.000000
3780 0.137500
3781 0.253333
I want to add an doc-id column starting with index 1 and change the value of column 0 to value. Expected output is
doc-id value
1 0.164560
2 0.000000
3 0.350000
4 0.700000
...
How can I do that?
If you want to treat this new column as an Index for the dataframe (as opposed to a column of data):
# adjust the index to start at 1 instead of 0
df.reindex(df.index+1, copy=False)
# add the doc_id name
df.index.name = "doc_id"
Use insert and then rename:
df.insert(0, 'doc-id', df.index + 1)
df = df.rename(columns={0:'value'})
print (df)
doc-id value
0 1 0.164560
1 2 0.000000
2 3 0.350000
3 4 0.700000
3778 3778 0.350000
3779 3779 0.000000
3780 3780 0.137500
3781 3781 0.253333
If need change index add 1 and then use rename with rename_axis:
df.index +=1
df = df.rename(columns={0:'value'}).rename_axis('doc-id')
print (df)
value
doc-id
1 0.164560
2 0.000000
3 0.350000
4 0.700000
3779 0.350000
3780 0.000000
3781 0.137500
3782 0.253333
df.reindex(df.index+1)