OAU CSC 201 Practice Quiz

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

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’.

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]’

+ operator is concatenation operator.

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.

Class is a user defined data type.

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

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.

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

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

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.

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.

// 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 prints the values substituted for a, b, a, in the same order. This operation is performed using the format function. Hence the output of the code is: ‘helloworldhello’.

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

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

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.

Error, objects of type float cannot be interpreted as an integer.

he function sys.version can help us to find the version of python that we are currently working on. It also contains information on the build number and compiler used. For example, 3.5.2, 2.7.3 etc. this function also returns the current date, time, bits etc along with the version.

Expression 1 is evaluated as: 2**9, which is equal to 512. Expression 2 is evaluated as 8**2, which is equal to 64. The last expression is evaluated as 2**(3**2). This is because the associativity of ** operator is from right to left. Hence the result of the third expression is 512.

Carefully look at the colons.

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

// is integer operation in python 3.0 and int(..) is a type cast operator.

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 formatting option print(“%Ns”,X) helps us add ‘N’ number of spaces before a given string ‘X’. Hence the output for the code snippet shown above will be 56 blank spaces before the string “san-foundry”.

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 loop is entered twice.

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

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.

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

The code shown above prints the appropriate option depending on the conditions given. The condition which matches is (9>0), and hence the output is: good.

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

Lists should be copied by executing [:] operation.

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 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’.

Loops over the values.

abcd a a a is the output as x is modified only after ‘abcd’ has been printed once.

The code shown above uses multiple decorators. The output of this code is:

    *****
    %%%%%
    hello
    %%%%%
    *****

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