[python 기초] 12 - 의외의 처리와 디버깅

$ ./user_input_int.py
Enter an integer number: abc
Traceback (most recent call last):
  File "./user_input_int.py", line 6, in 
    usr_num = int(usr_ip)
ValueError: invalid literal for int() with base 10: 'abc'

#!/usr/bin/python3

while True:
    try:
        usr_num = int(input("Enter an integer number: "))
        break
    except ValueError:
        print("Not an integer, try again")

print("Square of entered number is: {}".format(usr_num * usr_num))

$ ./user_input_exception.py
Enter an integer number: a
Not an integer, try again
Enter an integer number: 1.2
Not an integer, try again
Enter an integer number: 3
Square of entered number is: 9

$ python3 -m py_compile syntax_error.py
  File "syntax_error.py", line 3
    print "Have a nice day"
                          ^
SyntaxError: Missing parentheses in call to 'print'

$ python3 -m pdb if_elif_else.py
> /home/learnbyexample/python_programs/if_elif_else.py(3)()
-> num = 45
(Pdb) p num
*** NameError: name 'num' is not defined
(Pdb) n
> /home/learnbyexample/python_programs/if_elif_else.py(6)()
-> if num > 25:
(Pdb) p num
45
(Pdb) l
  1     #!/usr/bin/python3
  2
  3     num = 45
  4
  5     # only if
  6  -> if num > 25:
  7         print("Hurray! {} is greater than 25".format(num))
  8
  9     # if-else
 10     if num % 2 == 0:
 11         print("{} is an even number".format(num))
(Pdb) q

#!/usr/bin/python3

# -----         -----
def greeting():
    print("-----------------------------")
    print("         Hello World         ")
    print("-----------------------------")

# -----        -----
def sum_two_numbers(num1, num2):
    sum = num1 + num2
    print("{} + {} = {}".format(num1, num2, sum))

# -----         -----
def num_square(num):
    return num * num

# ----- main -----
def main():
    greeting()
    sum_two_numbers(3, 4)

    my_num = 3
    print(num_square(2))
    print(num_square(my_num))

if __name__ == "__main__":
    main()

$ ./functions_main.py
-----------------------------
         Hello World
-----------------------------
3 + 4 = 7
4
9

>>> import functions_main

>>> functions_main.greeting()
-----------------------------
         Hello World
-----------------------------

>>> functions_main.num_square()
Traceback (most recent call last):
  File "", line 1, in 
TypeError: num_square() missing 1 required positional argument: 'num'

>>> functions_main.num_square(5)
25

>>> functions_main.main()
-----------------------------
         Hello World
-----------------------------
3 + 4 = 7
4
9