Convenient way to use offset aliases to create a DateOffset?
#### Code Sample, a copy-pastable example if possible

```python
import pandas as pd

alias_1H = '1H'
alias_1M = '1M'

offset_dict = {alias_1H: ('hours',1), alias_1M: ('months',1)}

def freq_to_offset(freq):
    custom_dict = {offset_dict[freq][0] : offset_dict[freq][1]}
    return custom_dict

offset_1H = pd.tseries.offsets.DateOffset(**freq_to_offset(alias_1H))

offset_1M = pd.tseries.offsets.DateOffset(**freq_to_offset(alias_1M))
```
#### Problem description

Hello,

I would like to be able to use the same type of offset aliases as defined [here](https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#timeseries-offset-aliases) for date_range() and period_range() function to create DateOffset.

The way I have found is the one copied/pasted here above, but I find the code not that straight.
Please, is there any better way to achieve that?

I understand the reversed is already possible: from a DateOffset, getting its offset alias.
I ask if the round way is possible?

Thanks for your help!
Bests,