OAU CSC 201 Practice Quiz

in is a keyword.

Numbers starting with a 0 are octal numbers but 9 isn’t allowed in octal numbers.

The loop is entered twice.

All of the above examples show explicit conversion. However the expression int(’10.8’) results in an error.

In Python, to define a block of code we use indentation. Indentation refers to whitespaces at the beginning of the line.

Variable x is incremented and printed twice.

The result of the expression shown above is (6.0, 16.0). This is because the result is automatically rounded off to one decimal place.

NameError, i is not defined.

[::-1] reverses the list.

The formatting method {1:<10} represents the second positional argument, left justified in a 10 character wide field.

The code shown above demonstrates rebinding using a static method. This can be done with or without a decorator. The output of this code will be 100.

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’.

i takes values 0, 1, 2 and 3.

pip is a package manager for python. Which is also called Preferred Installer Program.

The code shown above first prints the word “Decorated” and then “ordinary”. Hence the output of this code is:
Decorated
Ordinary.

Loops over the values.

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.

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.

Here, ‘result’ is a list which is extending three times. When first time ‘extend’ function is called for ‘result’, the inner code generates a generator object, which is further used in ‘extend’ function. This generator object contains the values which are in ‘list1’ only (not in ‘list2’ and ‘list3’).
Same is happening in second and third call of ‘extend’ function in these generator object contains values only in ‘list2’ and ‘list3’ respectively.
So, ‘result’ variable will contain elements which are only in one list (not more than 1 list).

The code shown above converts the value 255 into hexadecimal, that is, 0xff. The value ‘FF’ into integer. Hence the output of the code shown is: (‘0xff’, 255, 255).

The line of code can be translated to state that ‘f’ is printed if the argument passed to the Boolean function amount to zero. Else ‘t’ is printed. The argument given to the Boolean function in the above case is ‘spam’, which does not amount to zero. Hence the output is t.

The above expressions are evaluated as: 2/2, 8/2, which is equal to (1.0, 4.0).

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.

The code shown above is used to check whether a particular item is a part of a given set or not. Since ‘a’ is a part of the set z, the output is true. Note that this code would result in an error in the absence of the quotes.

Let us consider an example wherein a=2. The binary form of 2 is 0010. When we left shift this value by 2, we get 1000, the value of which is 8. Hence if we want to multiply a given number ‘a’ by 4, we can use the expression: a<<2.

^ is the Binary XOR operator.

In the code shown above, the function mk() is the decorator. The function which is getting decorated is mk2(). The return function is given the name p().

If the truth method is not defined, the object is considered true. Hence the output of the code shown above is true.

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.

The code shown above prints 1234 for the format specified %d, ‘1234  ’ for the format specifier %-6d (minus ‘-‘ sign signifies left justification), and 001234 for the format specifier %06d. Hence the output of this code is: ‘integers:…1234…1234  …001234’

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.

Error, objects of type int aren’t iterable.

The expression int(1011,2) results in an error. Had we written this expression as int(‘1011’,2), then there would not be an error.

The code shown above returns a new list containing only those elements of the list l which do not amount to zero. Hence the output is: [1, 2, ‘hello’].

You can’t perform mathematical operation on string even if the string is in the form: ‘1234…’.

Since we have specified that the order of the output be: {a}, {0}, {abc}, hence the value of associated with {a} is printed first followed by that of {0} and {abc}. Hence the output of the code shown above is: ‘2.5, 10, [1, 2]’.

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.

Explanation: { } creates a dictionary not a set. Only set() creates an empty set.

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

math.pow() returns a floating point number.

The output that is required is 6, that is, row 2, item 3. This position is represented by the statement: A[1][2].

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

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

The prefix 0x specifies that the value is hexadecimal in nature. When we convert this hexadecimal value to binary form, we get the result as: ‘0b1000’.

i is not in x[1:].