Exercise: create a module and reuse code from it (1 h)

Extend the exercise from today by applying what you've just learned about packages and code reusability.

Outline

Put the function into a separate .py file
Create yet another function that takes the name of the region as an input and returns SST values for the corresponding region
Use import to access these functions from another file or a notebook
Create the wind speed data
Create a dictionary of data, whose keys are names of regions and values are lists of heat fluxes data
Save the dictionary to text file (bonus: to a json file), both keys and values

1. Put the function into a separate .py file

Copy a code block with the "heat flux" function from the previous exercise
Open a Python script (not a notebook!), e.g. "my_awesome_module.py" in the current working directory
Paste the code block in the file and make sure there are no syntax mistakes
Congratulations, you've just created a module!

2. Create yet another function that takes the name of the region as an input and returns SST values for the corresponding region

This function can look something like the one below
Feel free to modify or extend it
You can replace region_name by experiment_name or whatever you prefer
For convenience, make sure the length of the returned list is the same



In [1]:

    
def create_sst(region_name):
    """
    Create fake SST data (degC) for a given region
    
    Inputs
    ------
    region_name: ...continue the docstring...
    
    n: integer, optional. Length of the returned data list      
    
    Returns
    -------
    ...continue the docstring...
    """
    
#     if region_name == 'NS':
#         # North Sea
#         sst = list(range(5, 15, 1))
#     elif region_name == 
#         # Sea of Tranquility
#         sst =
#     elif region_name ==
#         sst = 
#     else:
#         raise ValueError('Input value of {} is not recognised'.format(region_name))
        
#     return sst

Once you are happy with this new function, put it in the same module too.

3. Use import to access these functions from another file or a notebook



In [2]:

    
# import my_super_awesome_module



In [3]:

    
# from my_super_awesome_module import heat_flux_function, create_sst

4. Create the wind speed data

You can just copy the line from the previous exercise



In [4]:

    
# wind_speed =

5. Create a dictionary of data, whose keys are names of regions and values are lists of heat fluxes data

Create a list of names of the regions/experiments
Create an empty dictionary, named hf_dict or whatever sounds better to you
Loop over the names, call the create_sst() function and assign it to a variable, e.g. fake_sst
Still inside the name-loop, write another loop to iterate over SST and wind values, just as you did in the previous exercise, and calculate the heat flux.
Assign the result to the corresponding key of hf_dict



In [5]:

    
# Your code here...

Print the result to test yourself.

6. Save the dictionary to text file (bonus: to a json file), both keys and values

You can copy the code for writing data to a text file from the previous exercise
Modify it so that the output file would include hf_dict's keys as row (column) names



In [6]:

    
# with open(...

Bonus



In [7]:

    
import json

Explore what json.dump() does.

Solution