In this section, I use Python and SQLAlchemy to do a basic climate analysis and data exploration of my climate database in the following stepd
-
Use the SQLAlchemy
create_engine()
function to connect to my SQLite database -
Use the SQLAlchemy
automap_base()
function to reflect tables into classes, and then save references to the classes namedstation
andmeasurement
. -
Link Python to the database by creating a SQLAlchemy session.
-
Perform a precipitation analysis and a station analysis
Precipitation Analysis
- Find the most recent date in the dataset.
- Using that date, get the previous 12 months of precipitation data by querying the previous 12 months of data.
- Select only the "date" and "prcp" values.
- Load the query results into a Pandas DataFrame. Explicitly set the column names.
- Sort the DataFrame values by "date".
- Plot the results by using the DataFrame
plot
method. - Use Pandas to print the summary statistics for the precipitation data. Station Analysis
- Design a query to calculate the total number of stations in the dataset.
- Design a query to find the most-active stations (that is, the stations that have the most rows).
- Design a query that calculates the lowest, highest, and average temperatures that filters on the most-active station id found in the previous query.
- Design a query to get the previous 12 months of temperature observation (TOBS) data.
Part 2: Design Your Climate App In this section, I designed a Flask API based on the queries that you just developed.
These are the following routes:
-
/
- Start at the homepage.
- List all the available routes.
-
/api/v1.0/precipitation
- Convert the query results from your precipitation analysis (i.e. retrieve only the last 12 months of data) to a dictionary using
date
as the key andprcp
as the value. - Return the JSON representation of your dictionary.
- Convert the query results from your precipitation analysis (i.e. retrieve only the last 12 months of data) to a dictionary using
-
/api/v1.0/stations
- Return a JSON list of stations from the dataset.
-
/api/v1.0/tobs
- Query the dates and temperature observations of the most-active station for the previous year of data.
- Return a JSON list of temperature observations for the previous year.
-
/api/v1.0/<start>
and/api/v1.0/<start>/<end>
- Return a JSON list of the minimum temperature, the average temperature, and the maximum temperature for a specified start or start-end range.
- For a specified start, calculate
TMIN
,TAVG
, andTMAX
for all the dates greater than or equal to the start date. - For a specified start date and end date, calculate
TMIN
,TAVG
, andTMAX
for the dates from the start date to the end date, inclusive.