Manually set 'freq' for specific datasets

[zqiao11]

Fix the bug in issue #107. Enable to manually set freq for the datasets in which freq=None using pd.infer_freq. If such datasets are not included in freq_dict, its freq will be set as 'H' by default.

[liu-jc]

I think we may want to avoid freq_dict and add an additional feature. See the detailed comments. Feel free to share your thoughts on this suggestion.

[liu-jc]

I am thinking maybe we can have an argument as in the main function like 'set_freq' and another argument for user-defined freq. Something like the following:

    # Define the `freq` argument with a default value
    parser.add_argument(
        '--freq',
        default='H',  # Set the default value
        help="The user specified frequency"
    )

    # Define an additional flag to detect if `--freq` is explicitly set
    parser.add_argument(
        '--set_freq',
        action='store_true',
        help="Flag to check if `freq` was explicitly set"
    )

Then if the command has set_freq, we directly set the freq to the user specified frequency. Otherwise, we use the current logic (i.e., infer the freq and if it's None, set to 'H'). Does it make sense?

I think in this way, we can avoid the hard-coded freq_dict and add more flexibilities for user to set the frequency. This additional feature should not affect the current command.

[zqiao11]

Yes, this method is better and more user-friendly. I will update accordingly. Thanks for the suggestions!

[zqiao11]

I think we can only use one argument? If freq is not given/modified in the command, the codes will use 'H' by default. It seems not necessary to use another set_freq argument.

[zqiao11]

Currently, I’m only using a single argument, freq. From my perspective, if freq can be inferred automatically, there's no need to enable users to set it manually to another predefined value.

Additionally, I’ve added a prompt to notify users about the setting of freq. This lets them know if the freq of a dataset can be inferred automatically. If not, they can manually specify the correct freq with the argument. Without such prompting, it would be difficult for the users to notice if a mismatched freq is used.

[liu-jc]

LGTM. Thanks for your help. I will merge this.