1.set_index
DataFrame can be set by the set_index method, which allows you to set both a single index and a composite index.
dataframe.set_index (keys, drop=True, append=False, inplace=False, verify_integrity=False)
append add a new index, drop is False, inplace is True, the index will be restored to the column
 

In [307]: data
Out[307]: 
     a    b  c    d
0  bar  one  z  1.0
1  bar  two  y  2.0
2  foo  one  x  3.0
3  foo  two  w  4.0

In [308]: indexed1 = data.set_index('c')

In [309]: indexed1
Out[309]: 
     a    b    d
c               
z  bar  one  1.0
y  bar  two  2.0
x  foo  one  3.0
w  foo  two  4.0

In [310]: indexed2 = data.set_index(['a', 'b'])

In [311]: indexed2
Out[311]: 
         c    d
a   b          
bar one  z  1.0
    two  y  2.0
foo one  x  3.0
    two  w  4.0

 
2.reset_index
 
Reset_index
dataframe.reset_index (level=None, drop=False, inplace=False, col_level=0, col_fill= “)
level controls the index of the specific level to be restored
drop to False, the index column will be restored to the normal column, otherwise it will be lost

In [318]: data
Out[318]: 
         c    d
a   b          
bar one  z  1.0
    two  y  2.0
foo one  x  3.0
    two  w  4.0

In [319]: data.reset_index()
Out[319]: 
     a    b  c    d
0  bar  one  z  1.0
1  bar  two  y  2.0
2  foo  one  x  3.0
3  foo  two  w  4.0