# Any way to detect division by zero?

In Sage, is there any way (function call) to check whether a given expression will produce division by zero error. Is something like the following possible?

if IsDivisionByZero(expr): return False

In Sage, is there any way (function call) to check whether a given expression will produce division by zero error. Is something like the following possible?

if IsDivisionByZero(expr): return False

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4

You can use Python `try...except`

blocks to catch a `ZeroDivisionError`

. For example, I define the two functions

```
def foo(x):
return 1/x
def bar(x):
try:
return 1/x
except ZeroDivisionError:
# error handling: do whatever you want here
print "Returning positive infinity..."
return Infinity
```

This is what the output looks like when giving various inputs into these two functions.

```
sage: foo(1)
1
sage: foo(0)
Traceback (click to the left of this block for traceback)
...
ZeroDivisionError: Rational division by zero
sage: bar(1)
1
sage: bar(0)
Returning positive infinity...
+Infinity
```

You can use `try...except`

blocks outside of function definitions as well.

2

Something like this:

```
def temp(x):
try:
return 3/x
except ZeroDivisionError:
return False
```

Then

```
sage: temp(2)
3/2
sage: temp(0)
False
```

Asked: **
2010-12-08 12:02:45 -0600
**

Seen: **513 times**

Last updated: **Dec 09 '10**

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