OAU CSC 201 Practice Quiz

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.

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’.

i is not in x[1:].

SyntaxError, True is a keyword and it’s value cannot be changed.

The finally block is executed even there is a return statement in the try block.

String x is not being altered and i is in x[:-1].

Objects of type set have no attribute values.

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

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

List data type can store any values within it.

[::-1] reverses the list.

OverflowError, cannot convert float infinity to integer.

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

The formatting expression accepts either a single substitution value, or a tuple of one or more items. Since single item can be given either by itself or within the tuple, a tuple to be formatted must be provided as a tested tuple. Hence the output of the code is: >>> ‘%s’ %((1.23,),).

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.

The order of precedence is: %, +. Hence the expression above, on simplification results in 4 + 3 = 7. Hence the result is 7.

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 highest precedence is that of the exponentiation operator, that is of **.

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’

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.

The code shown above returns the address on the function ordi first, after which the word “Ordinary” is printed. Hence the output of this code is:
Address
Ordinary.

The above expression returns the output 000345. It adds the required number of zeroes before the given number in order to make the number of digits 6 (as specified in this case).

For order of precedence, just remember this PEMDAS (similar to BODMAS).

Variable x is incremented and printed twice.

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

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 string.

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 value of the expression (2**2)**3 = 4**3 = 64. When the expression 2**2**3 is evaluated in python, we get the result as 256, because this expression is evaluated as 2**(2**3). This is because the associativity of exponentiation operator (**) is from right to left and not from left to right.

The code shown above shows two functions. In both the cases the right operand is returned. This is because each function is evaluated from left to right. Since the left operand is false, it is assumed that the right operand must be true and hence the right operand is returned in each of the above case.

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

i takes values 0, 1, 2 and 3.

Variable names can be of any length.

Modulus operator gives the remainder. So, 22%3 gives the remainder, that is, 1.

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

Execute help(math.trunc) to get details.

Understanding Arithmetic Operators with Strings:

1. * (Multiplication):
• Strings can be multiplied with integers to create repeated copies of the string.
• Example:

print(“abc” * 3) # Output: abcabcabc

• Allowed with strings.

2. – (Subtraction):
• Subtraction is not defined for strings in Python. You cannot subtract one string from another.
• Example:

print(“abc” – “a”) # This will raise a TypeError.

• Not allowed with strings.

3. + (Addition):
• Strings can be concatenated (joined) using the + operator.
• Example:

print(“abc” + “def”) # Output: abcdef

• Allowed with strings.

4. All of the mentioned:
• Since both * and + are allowed with strings, not all arithmetic operators are disallowed. Only – (subtraction) cannot be used with strings.

Correct Answer:

b) –

Subtraction (-) is the arithmetic operator that cannot be used with strings in Python.

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

Class is a user-defined data type.

// is the operator for truncation division. It is called so because it returns only the integer part of the quotient, truncating the decimal part. For example: 20//3 = 6.

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).

When both of the operands are integer then python chops out the fraction part and gives you the round off value, to get the accurate answer use floor division. This is floor division. For ex, 5/2 = 2.5 but both of the operands are integer so answer of this expression in python is 2. To get the 2.5 answer, use floor division.

The expression shown above is evaluated as: 2+9*(36-8)/10, which simplifies to give 2+9*(2.8), which is equal to 2+25.2 = 27.2. Hence the result of this expression is 27.2.

Python language is designed by a Dutch programmer Guido van Rossum in the Netherlands.

‘.py’ is the correct extension of the Python file. Python programs can be written in any text editor. To save these programs we need to save in files with file extension ‘.py’.

In the code shown above, we have used a decorator in order to avoid the Zero Division Error. Hence the output of this code is:

    hello
    NO

Execute in the shell.