OAU CSC 201 Practice Quiz

The order of precedence is: **, //, +. The expression 4+2**5//10 is evaluated as 4+32//10, which is equal to 4+3 = 7. Hence the result of the expression shown above is 7.

The code shown above shows the formatting option on the same value, that is 4.56, where in the second case, the value is enclosed in a list. Hence the output of the code shown above is:
‘4.56’, ‘[4.56]’

i takes values 0, 1, 2 and 3.

The expression shown above results in the output 456.

In the code shown above, @sf is not a decorator but only a decorator line. The ‘@’ symbol represents the application of a decorator. The decorator here is the function mk.

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

eval can be used as a variable.

Within the subject string, curly braces designate substitution targets and arguments to be inserted either by position or keyword. Hence the output of the code shown above:’hello, good,and morning’.

OverflowError, cannot convert float infinity to integer.

In the snippet of code shown above, three values are inserted into the target string. When we insert more than one value, we should group the values on the right in a tuple. The % formatting expression operator expects either a single item or a tuple of one or more items on its right side.

The instance of the string returned by upper() is being printed.

[::-1] reverses the string.

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.

Loops over key, value pairs.

The expressions are evaluated as: 4%3 and 6//2 respectively. This results in the answer (1,3). This is because the associativity of both of the expressions shown above is left to right.

Pickling is the process of serializing a Python object, that is, conversion of a Python object hierarchy into a byte stream. The reverse of this process is known as unpickling.

cmp(x, y) returns 1 if x > y, 0 if x == y and -1 if x < y.

Explanation: Objects of type int aren’t subscriptable. However, if the statement was x[i], an error would not have been thrown.

The code ‘There are %d %s birds.’ %(4, blue) results in the output: There are 4 blue birds. When we insert more than one value, we should group the values on the right in a tuple.

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

Execute in the shell.

The expression int(‘1111’,2) gives the result 15. The expression int(‘1111’, 10) will give the result 1111.

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

The one’s complement of a value is obtained by simply changing all the 1’s to 0’s and all the 0’s to 1’s. Hence the one’s complement of 110010101 is 001101010.

eval can be used as a variable.

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

The output of bin(10-2) = 0b1000 and that of bin(12^4) is ob1000. Hence the output of the above expression is: 0b10000b1000.

The output of f(0, 2) is 0, since o%2 is equal to 0. The output of the f(2, 0) is a Zero Division Error. We can make use of decorators in order to avoid this error.

In the code shown above, the value for a is substituted by l[0], that is ‘H’, the value of b is substituted by l[-1], that is ‘O’ and the value for c is substituted by l[1:3]. Here the use of *p is to unpack a tuple items into individual function arguments.

The binary form of -44 is 00101100. The one’s complement of this value is 11010011. On adding one to this we get: 11010100 (two’s complement).

The binary form of 1 is 0001. The expression x<<2 implies we are performing bitwise left shift on x. This shift yields the value: 0100, which is the binary form of the number 4.

Lists should be copied by executing [:] operation.

Many languages have been implemented using both compilers and interpreters, including C, Pascal, and Python.

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 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’].

The code shown above is used to swap the contents of two memory locations using bitwise X0R operator. Hence the output of the code shown above is: 20 10.

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

Tuples are represented with round brackets.

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

Dictionary stores values in terms of keys and values.

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().

The result of the expression shown will be 1011. This is because we have not specified the base in this expression. Hence it automatically takes the base as 10.

The elements of the tuple are accessed by their indices.