pandas series get element by index code example
Example 1: finding the index of an element in a pandas df
In [48]: a
Out[48]:
c1 c2
0 0 1
1 2 3
2 4 5
3 6 7
4 8 9
In [49]: a.c1[a.c1 == 8].index.tolist()
Out[49]: [4]
Example 2: pandas df by row index
indices = [133, 22, 19, 203, 14, 1]
df_by_indices = df.iloc[indices, :]
Example 3: add an index column in range dataframe
df = df.loc[df.index.repeat(df['a'])]
df['c'] = df.groupby(level=0).cumcount() + 1
df = df.reset_index(drop=True)
print (df)
a b c
0 1 x 1
1 2 y 1
2 2 y 2
3 3 z 1
4 3 z 2
5 3 z 3