OAU CSC 201 Practice Quiz

in is a keyword.

In python, power operator is x**y i.e. 2**3=8.

Python has a nifty feature called documentation strings, usually referred to by its shorter name docstrings. DocStrings are an important tool that you should make use of since it helps to document the program better and makes it easier to understand.

All of the operators shown above have associativity from left to right, except exponentiation operator (**) which has its associativity from right to left.

Objects of type int have no attribute upper().

The loop is entered twice.

The @ symbol can be used as an alternate way to specify a function that needs to be decorated. The output of the codes shown above is the same. Hence they are equivalent. Therefore this statement is true.

The ^ operator represent bitwise XOR operation. &: bitwise AND, | : bitwise OR and ! represents bitwise NOT.

Any odd number on being AND-ed with 1 always gives 1. Any even number on being AND-ed with this value always gives 0.

The function len() returns the length of the number of elements in the iterable. Therefore the output of the function shown above is 4.

Objects of type set have no attribute values.

Class is a user-defined data type.

The def keyword is used to create, (or define) a function in python.

~x is equivalent to -(x+1).

Cause a decimal value of 0 to appear as output.

Lists should be copied by executing [:] operation.

The expression shown above normally returns the value with 6 decimal points if it is not specified with any number. Hence the output of this expression will be: 34.000000 (6 decimal points).

The Boolean function returns true if the argument passed to the bool function does not amount to zero. In the first example, the string ‘False’ is passed to the function bool. This does not amount to zero and hence the output is true. In the second function, an empty list is passed to the function bool. Hence the output is false.

range(int(2.0)) is the same as range(2).

This is a built-in function which rounds a number to give precision in decimal digits. In the above case, since the number of decimal places has not been specified, the decimal number is rounded off to a whole number. Hence the output will be 5.

The built in function vars() returns a dictionary containing all the variables that exist in the place. Hence the output of the code shown above is: {‘a’ : ‘hello’, ‘q’ : 10, ……..plus built-in names set by Python….}

Within the subject string, curly braces represent substitution targets and arguments to be inserted. Hence the output of the code shown above:
‘hello, world, universe’.

The result of the expression shown above is 1.0 because print rounds off digits.

Padding is done towards the right-hand-side first when the final string is of even length.

Loops over the elements of the set and prints them.

The code shown above results in an error. This is because we have switched from automatic field numbering to manual field numbering, that is, from {} to {1}. Hence this code results in an error.

[::-1] reverses the list.

The code shown above displays the string method to round off a given decimal number to two decimal places. Hence the output of the code is: ‘1.23’.

OverflowError, cannot convert float infinity to integer.

SyntaxError, there shouldn’t be a space between + and = in +=.SyntaxError, there shouldn’t be a space between + and = in +=.

Infinity is a special case of floating point numbers. It can be obtained by float(‘inf’).

Built-in functions and user defined ones. The built-in functions are part of the Python language. Examples are: dir(), len() or abs(). The user defined functions are functions created with the def keyword.

A folder of python programs is called as a package of modules.

The above expression is an example of explicit conversion. It is evaluated as: float(4+int(2.39)%2) = float(4+2%2) = float(4+0) = 4.0. Hence the result of this expression is 4.0.

The function seed is a function which is present in the random module. The functions sqrt and factorial are a part of the math module. The print function is a built-in function which prints a value directly to the system output.

As the value of i or x isn’t changing, the condition will always evaluate to True.

Each object in Python has a unique id. The id() function returns the object’s id.

The @ symbol along with the name of the decorator function can be placed above the definition of the function to be decorated works as an alternate way for decorating a function.

Coercion is the implicit (automatic) conversion of operands to a common type. Coercion is automatically performed on mixed-type expressions. The expression 1.7 % 2 is evaluated as 1.7 % 2.0 (that is, automatic conversion of int to float).

The string x is being shortened by one character in each iteration.

To write single-line comments in Python use the Hash character (#) at the beginning of the line. It is also called number sign or pound sign. To write multi-line comments, close the text between triple quotes.
Example: “”” comment
text “””

The expression not(-6<0 or -6>10) returns the output False.
The expression -6>=0 and -6<=10 returns the output False.
The expression not(-6<10 or -6==10) returns the output False.
The expression not(-6>10 or -6==10) returns the output True.

In the code shown above, the decorator helps us to prefix the dollar sign along with the value. Since the second argument is zero, the output of the code is: $100.