CODEWITHSUNDEEP
pythonif-statementexceptiontry-catch
Liqun
Liqun

Reputation: 4171

Try except clause adjacent to if statement conflict

Let me explain the problem with some demo codes:

 def my_func:
    if not a:
        #operations A here.
    try:
        #operations B here. 
    except:
        #operations C here.

The problem here is that the try-except clause seems to be included into the if statement. Only if "not a" is True, the try-except clause statements would be executed, other wise they would never be executed.

I tried to shrink some indent space before try-except clause as follow:

def my_func:
    if not a:
        #operations A here.
try:
    #operations B here. 
except:
    #operations C here.

Now everything seems to work as try-except is executed independently with the if statement.

Any explanation is really appreciated.

Upvotes: 0

Views: 250

Answers (1)

Bakuriu
Bakuriu

Reputation: 101959

You have mixed tabs with spaces in your indentation, this lead the interpreter to misinterpret the indentation levels, thinking that the try was one level higher:

>>> if True:
...     if True:   # indentation with 4 spaces. Any number will do
...     a = 1      # indentation with a tab. Equals two indents with spaces
...     else:      # indentation with 4 spaces
...     a = 2
... 
>>> a   # as if the "a = 1" was inside the second if
1

To check whether this is the problem launch the program via python -tt which raises an error if it finds mixed tabs and spaces. Also note that when using python3 it automatically runs with the -tt option, not allowing mixing tabs and spaces.

Upvotes: 1

Related Questions