change numerical values to categorical names

[scidam]

How can we help, if there is no code except the dictionary?
If you use pandas, you can do it easily, e.g.

In [75]: import pandas as pd
    ...:
    ...: mapper = {1: 'John', 2: 'July'}
    ...:
    ...: df = pd.DataFrame({'names': [1, 2, 1, 1], 'age': [10, 20, 10, 10]})
    ...:
    ...: df.names.map( mapper)

Output:
Out[75]:
0    John
1    July
2    John
3    John
Name: names, dtype: object