Functions, namespace, memory management
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Required course material for the lesson
Powerpoint: Functions - this will be short as it is a reminder.
Powerpoint: Namespace.
Powerpoint: Memory management.
Video: Functions in Python
Video: Examples and identifying data types
Resource: Example code - Functions
Video: Live Coding
Subjects covered
- Short about functions
- Namespace in Python
- Memory management
Exercises to be handed in
- Make a function fastaread(filename) which takes a filename as a parameter and returns 2 lists, first list is the headers, second list is the sequences (as single strings without whitespace). Add appropriate error handling to the function. You can test your function on the file dna7.fsa.
- Make a function fastawrite(filename, headers, sequences) which takes a filename, a list of headers and a corresponding list of sequences as parameters and writes the fasta file. Add appropriate error handling to the function. You can test your function on the file dna7.fsa.
- Make a function that take a DNA sequence (string) as parameter and return the complement strand (reverse complement). Make the function generic and portable, i.e. not dependent on any external factors. Together with the functions you made in exercise 3 & 4, read the fasta entries in file dna7.fsa and write the complement strands in the new file revdna7.fsa. Add 'Complement strand' to each header.