OAU CSC 201 Practice Quiz

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.

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

Loops over the keys of the dictionary.

The expression shown above does not result in an error. The output of this expression is -%5d0 989. Hence this statement is incorrect.

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.

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).

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

The elements of the tuple are accessed by their indices.

Here i i i i i … printed continuously because as the value of i or x isn’t changing, the condition will always evaluate to True. But also here we use a citation marks on “i”, so, here i treated as a string, not like a variable.

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

The expression shown above is an example of explicit conversion. It is evaluated as int(43.55+1) = int(44.55) = 44. Hence the result of this expression is 44.

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

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

Carefully look at the colons.

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.

Python first searches for the local, then the global and finally the built-in namespace.

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

Functions are reusable pieces of programs. They allow you to give a name to a block of statements, allowing you to run that block using the specified name anywhere in your program and any number of times.

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’

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

eval can be used as a variable.

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.

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.

Objects of type int have no attribute upper().

Objects of type set have no attribute values.

The loop does not terminate since i is never an even number.

True, False and None are capitalized while the others are in lower case.

he binary form of the number 29 is 11101. Hence the output of this expression is ‘0b11101’.

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.

The else part is not executed if control breaks out of the loop.

The code shown above prints the values substituted for p and q in the same order. Note that there is no blank space between p and q. Hence the output is: sanfoundry.

[::-1] reverses the list.

The \n adds a new line.

Loops over the elements of the set and prints them.

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 else part is executed when the condition in the while statement is false.

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 code snippet shown above results in an error because the above formatting option works only if ‘X’ is a number. Since in the above case ‘X’ is a string, an error is thrown.

When the value of x is equal to 8 (1000), then x>>2 (bitwise right shift) yields the value 0010, which is equal to 2. Hence the value of x is 8.

0O11 is an octal number.

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.

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.

math.pow() returns a floating point number.

The symbol ‘&’ represents bitwise AND. This gives 1 if both the bits are equal to 1, else it gives 0. The binary form of 15 is 1111 and that of 12 is 1100. Hence on performing the bitwise AND operation, we get 1100, which is equal to 12.

Id in this case will be the attribute of the instance.

In order to add ‘n’ blank spaces after a given string ‘S’, we use the formatting option:(“%-ns”%S).

The output of the expression above will be 22.19. This expression specifies that the total number of digits (including the decimal point) should be 5, rounded off to two decimal places.

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 expression shown above results in the output 456.

+’ cannot be converted to a float.

In the code shown above, we have not passed any parameter to the function p. Hence the output of this code is: hello.