This question already has answers here:
Why does comparing strings using either '==' or 'is' sometimes produce a different result?
(15 answers)
Closed 9 years ago.
If I understand correctly, the is operator can take the place of ==.
Why when I write
if inpty == "exit":
return
does the function exit, but when I write
if inpty is "exit":
return
the function does not?
inpty is the value of the input.
is compares identity, whereas == compares equality.
In other words, a is b is the same as id(a) == id(b).
because in this case, the is operator is testing identity, not the value.
Related
This question already has answers here:
How do "and" and "or" act with non-boolean values?
(8 answers)
Closed 5 months ago.
Can someone please explain why the following code comes out as "geeks" in the console?
def check():
return "geeks"
print(0 or check() or 1)
I'm assuming that Python recognizes the boolean operator, thus treating 0 == False?
So does that mean every time boolean operators are used, the arguments are treated as True/False values?
The reason that "geeks" will be printed is that or is defined as follows:
The Python or operator returns the first object that evaluates to true
or the last object in the expression, regardless of its truth value.
When check() returns the string "geeks", that value evaluates to True because it is a non-empty string. That value is then the first term in the or expression that evaluates to True, so that value is the result of the entire expression, and so is what gets printed.
This question already has answers here:
How to test multiple variables for equality against a single value?
(31 answers)
Closed 12 months ago.
I'm a beginner in Python and I'm trying to write an IF statement with multiple OR conditions in the expression. My problem is that the expression is only "True" for the first OR condition.
def rna_length(mrna):
if (mrna[-3:]) == ("UGA" or "UAA" or "UAG"):
return print("TRUE!")
else:
return print("False")
rna_length('AUGAGGCACCUUCUGCUCCUUAA')
I was expecting True after running the code but the code is printing False.
Kindly help me understand my mistake.
Here is how to do:
if mrna[-3:] in ("UGA", "UAA", "UAG"):
("UGA" or "UAA" or "UAG") will return "UGA" because the operator or return the first non-False value. Since non-empty strings arn't False the first value is returned.
This question already has answers here:
Python list - True/False first two elements? [duplicate]
(2 answers)
Closed 2 years ago.
In a Clash of Code, I've seen this interesting operator thing:
print(["false","true"][i == n])
I haven't seen this before. What's the name of this and what does it do?
It's not exactly an operator but rather the second condition is being used as an index for the ["false", "true"] list.
In case i == n this will be true. Let me remind you that true in python equals to 1
int(True) // = 1
Therefore if i == n, it will be equal to one and will print the element with index one from the list which is "true".
In case i != n, it will be False, equals to 0 which will print the first element from the array which is "false".
This a comparison Operator,
it compares the value or equality of two objects, whereas the Python is operator checks whether two variables point to the same object in memory. In the vast majority of cases, this means you should use the equality operators == and != , except when you're comparing to None.
Output: True or False
Usage: Is used to check whether 2 expressions give the same value.
This question already has answers here:
"is" operator behaves unexpectedly with integers
(11 answers)
Is there a difference between "==" and "is"?
(13 answers)
Closed 3 years ago.
I'm using the pow function and found out I had a bug in my code because == and is were not having the same behavior.
Here goes an example: pow(3, 47159012670, 47159012671) == 1 returns True but pow(3, 47159012670, 47159012671) is 1 returns False.
I'd like to know what is it that I'm not getting.
The difference between is and == is:
a1 is a2 # return True
only when they share the same location or id in memory, that means when id(a1) and id(a2) are the same. I hope this will help more.
This question already has answers here:
Is there a difference between "==" and "is"?
(13 answers)
Closed 6 years ago.
Two items may be unequal in many ways. Can python tell what is the reason?
For example: 5 is not 6, int(5) is not float(5), "5" is not "5 ", ...
Edit: I did not ask what kinds of equality test there are, but why and how those are not equal. I think my question is not duplicate.
There are several checks you can do:
# Both variables point to the same object (same memory space)
a is b
# Both variables evaluates to the same value
a == b
# Both variables are of same type
type(a) == type(b)
is checks if the two items are the exact same object. This check identity
== checks if the two objects are equal values
You use is not None to make sure that the object the "real" none and not just false-y.