get column of dataframe code example

Example 1: python - subset specific columns name in a dataframe

columns = ['b', 'c']
df1 = pd.DataFrame(df, columns=columns)

Example 2: how to find columns of a dataframe

list(my_dataframe.columns.values)

Example 3: select columns pandas

df1 = df.iloc[:,0:2] # Remember that Python does not slice inclusive of the ending index.

Example 4: 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