Logical-operators exercise in Python-CodePudding

really struggling with this simple problem below. struggling to code a line of code that include all the possible cases.

any suggestion would be much appreciated

the code has to print True if

feel_prepared = True

and

review_time > = 2

But if test_percent >=20 than we need a review_time of at least 4 hours to get a TRUE

test_percent = 21
review_time = 2
feel_prepared = True

print(prepared and (test_percent >= 20 or test_percent <20) and review_time >=4))

but doesn't work if feel_prepared = True, review_time = 2 and test_percentage \<20

CodePudding user response：

One approach would be to break this problem into smaller ones, and solve it iteratively.

Let's review the first part of the exercise:

the code has to print True if feel_prepared = True and review_time > = 2

So you pass the test when feel_prepared == True and review_time >= 2.

Now for the second part:

But if test_percent >=20 than we need a review_time of at least 4 hours to get a TRUE

What it says is that in some cases you pass the test with feel_prepared == True and review_time >= 4

You can pass with either feel_prepared == True and review_time >= 2 or feel_prepared == True and review_time >= 4. The only difference is test_percent.

What the exercise text says is when test_percent is lower than 20, you pass with feel_prepared == True and review_time >= 2, and when it's equal or higher than 20, you pass with feel_prepared == True and review_time >= 4.

So if it's test_percent < 20 and feel_prepared == True and review_time >= 2, you pass. Or you pass when it's test_percent >= 20 and feel_prepared == True and review_time >= 4.

Thus,

(test_percent < 20 and feel_prepared == True and review_time >= 2) or (test_percent >= 20 and feel_prepared == True and review_time >= 4)

You can then apply distributive law and write

feel_prepared == True and ((test_percent < 20 and review_time >= 2) or (test_percent >= 20 and review_time >= 4))

You can also notice that when you feel_prepared and review_time >= 4, you always pass. But when 2 <= review_time < 4, you pass only if test_score < 20:

feel_prepared == True and (review_time >= 4 or (review_time >= 2  and test_percent < 20))

CodePudding user response：

I think this solves the problem:

test_percent = 19
review_time = 2
feel_prepared = True

statement = feel_prepared and ((test_percent >= 20 and review_time >=4) or (test_percent < 20 and review_time >=2))

print(statement) #True because test_percent < 20 and review_time >= 2

test_percent = 21
review_time = 2
feel_prepared = True

statement = feel_prepared and ((test_percent >= 20 and review_time >=4) or (test_percent < 20 and review_time >=2))

print(statement) #False because test_percent >= 20 and review_time < 4

CodePudding user response：

I believe your problem is with the parenthesis, and fact that (test_percent < 20 or test_percent >= 20) always return True.

I don't know if I understood correctly all the cases, but I think this is the correct :)

print((prepared and review_time >=2 and test_percent < 20) or (prepared and review_time >=4 and test_percent >= 20)