How would you delete columns from a dataframe ?

How would you delete rows from a dataframe ?

Consider following Series object namely S :

0      0.430271                          
1      0.617328                          
2     -0.265421                          
3     -0.836113                              
dtype:float64                                

What will be returned by following statements ?

(a) S * 100

(b) S > 0

(c) S1 = pd.Series(S)

(d) S2 = pd.Series(S1) + 3

What will be the values of Series objects S1 and S2 created above ?

Consider the same Series object, S, given in the previous question. What output will be produced by following code fragment ?

S.index = ['AMZN', 'AAPL', 'MSFT', 'GOOG']
print(S) 
print(S['AMZN'])
S['AMZN'] = 1.5
print(S['AMZN'])
print(S)