Module 1

Text and strings

Text is called a string.

Text inside Python

When you write text in Python, you surround it with quotation marks. This piece of text is called a string (short for string of characters).

Python"ATGC" is a string.
print("ATGC")
ATGC
Biology connection

In bioinformatics, a DNA sequence can initially be represented in Python as text: "ATGCGT". Python calls this a string, or str for short.

PythonEven a single character in quotes is a string.
print("A")
A
A common mistake

Forgetting the closing quote makes Python throw a SyntaxError. The error panel will try to explain it. If you see it, check that every opening quote has a matching closing one.

Your task

Print a string

  • Print the DNA sequence ATGC as a string.
  • Remember the quotation marks.
Remember

A string is text inside quotes. Python remembers it exactly as you write it, including spaces.