• 1. Terms
• 2. Types of error
  • 2.1. Syntax Error
  • 2.2 Exception
• 3. Error Handing
  • 3.1. Try Except

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1. Terms

• Bug
  • problems occurring in SW
• Debugging
  • fixing bugs

2. Types of error

2.1. Syntax Error

If there's syntax error, code can't be excuted. '^' indciates the position where the error is detected

• EOL / EOF
  • End of Line / End of File: error related to brackets
• IndentationError
  • Base class for syntax errors related to incorrect indentation

2.2 Exception

Simply speaking, errors except syntax errors. The error occurs during running the code.

• IndexError
  • Raised when a sequence subscript is out of range.
• ImportError
  • Raised when the import statement has troubles trying to load a module.
• KeyError
  • Raised when a mapping (dictionary) key is not found in the set of existing keys.
• KeyboardInterrupt
  • Raised when the user hits the interrupt key (normally Control-C or Delete).
• ModuleNotFoundError
  • A subclass of ImportError which is raised by import when a module could not be located.
• NameError
  • Raised when a local or global name is not found.
• TypeError
  • Raised when an operation or function is applied to an object of inappropriate type.
• ValueError
  • Raised when an operation or function receives an argument that has the right type but an inappropriate value.
• ZeroDivisionError
  • Raised when the second argument of a division or modulo operation is zero

3. Error Handing

3.1. Try Except

Basic Structure

try:
    # anyway try this code
except:
    # When Error is occured
else:
    # When Error is not occured
finally:
    # Always

Basic Structure Example

try:
    f = open('nofile.txt')
except FileNotFoundError:
    print('There is no file')
else:
    print('Starts reading file')
    print(f.read())
    print('Ends reading file')
    f.close()
finally:
    print('Ends the program')

Applications

try:
    # try this code
except <Errorname> as <Nickname>:
    # When Nickname(Errorname) occured

try:
    # try this code
except <Error1, Error2>:
    # Erorr1 or Error2 occured

try:
    # try this code
except <Error1>:
    # Erorr1 occured
except <Error2>:
    # Erorr2 occured, which is not Error 1
except:
    # Some kinds of Error occured, which is not Error 1 or 2