Difference between revisions of "W2653 CSV File Processing"
From Coder Merlin
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== Exercises == | == Exercises == | ||
# Design a class that will contain each field in a metar as a separate property. Pay close attention to the type of each field. | # Design a class that will contain each field in a metar as a separate property. Pay close attention to the type of each field. | ||
# Create an initializer that accepts a series of ''fields'' of the expected type | # Create an initializer that accepts a series of ''fields'' of the expected type | ||
# Create a convenience initializer that accepts a series of strings, one for each field | # Create a convenience initializer that accepts a series of strings, one for each field | ||
# Create a convenience initializer that accepts a single string, in a format identical to that in the sample file | # Create a convenience initializer that accepts a single string, in a format identical to that in the sample file | ||
# Support the CustomStringConvertible protocol, providing a ''reasonable'' description of the data encapsulated in the class. | # Support the CustomStringConvertible protocol, providing a ''reasonable'' description of the data encapsulated in the class. | ||
Hints: | |||
* In some cases you may opt to use more than one property for a single field in the file. | |||
* Think carefully about whether or not a property should be optional | |||
== Key Concepts == | == Key Concepts == | ||
Revision as of 21:07, 26 March 2019
Within these castle walls be forged Mavens of Computer Science ...
— Merlin, The Coder
CSV File Processing[edit]
This tutorial will provide an introduction about processing CSV files.
Research[edit]
- Read CSV Files (Creativyst)
- Read ICAO Airport Codes (Wikipedia)
- Read Aviation Weather Center Mission (US Government)
- Read Metar Overview (Wikipedia)
- Read Initialization (Swift Documentation) - Read only the section on convenience initializers
Experiment[edit]
Create a new directory in your ~/projects folder, named project-2651. Then, download this file Example-metars.csv to that directory.
cd ~/projects
mkdir project-2651
cd project-2651
wget https://wiki.codermerlin.com/mediawiki/images/1/15/Example-metars.csv
View the file in emacs:
emacs Example-metars.csv
Carefully observe the file. Remember that the "\" character as the last character in a line in emacs is a line-continuation character. (For reference, you may read Continuation-Lines.) You'll probably find it much easier to read most lines if you maximize the width of your window.
Questions:
- On which line does the actual data begin?
- How could you programmatically make this determination?
- What is the purpose of the immediately preceding line?
- How are records delimited?
- How are fields delimited?
Create a new file in the current directory, "main.swift". Perform all exercises in this lab in that file.
Exercises[edit]
- Design a class that will contain each field in a metar as a separate property. Pay close attention to the type of each field.
- Create an initializer that accepts a series of fields of the expected type
- Create a convenience initializer that accepts a series of strings, one for each field
- Create a convenience initializer that accepts a single string, in a format identical to that in the sample file
- Support the CustomStringConvertible protocol, providing a reasonable description of the data encapsulated in the class.
Hints:
- In some cases you may opt to use more than one property for a single field in the file.
- Think carefully about whether or not a property should be optional
