OAU CSC 201 Practice Quiz

The \n adds a new line.

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

The binary value of 0x35 is 110101 and that of 0x75 is 1110101. On OR-ing these two values we get the output as: 1110101, which is equal to 117. Hence the result of the above expression is 117.

Infinity is a special case of floating point numbers. It can be obtained by float(‘inf’).

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 function not returns true if the argument amounts to false, and false if the argument amounts to true. Hence the first function returns false, and the second function returns false.

As the value of i or x isn’t changing, the condition will always evaluate to True.

Carefully look at the colons.

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).

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 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.

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

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).

To write single-line comments in Python use the Hash character (#) at the beginning of the line. It is also called number sign or pound sign. To write multi-line comments, close the text between triple quotes.
Example: “”” comment
text “””

Python is an interpreted programming language, which supports object-oriented, structured, and functional programming.

Execute in the shell.

(element,) is not the same as element. It is a tuple with one item.

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.

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]’.

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.

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

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

All the statements will execute successfully but at the cost of reduced readability.

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

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.

When prefixed with the letter ‘r’ or ‘R’ a string literal becomes a raw string and the escape sequences such as \n are not converted.

Bitwise XOR gives 1 if either of the bits is 1 and 0 when both of the bits are 1.

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.

Addition and Subtraction” are at the same precedence level. Similarly, “Multiplication and Division” are at the same precedence level. However, Multiplication and Division operators are at a higher precedence level than Addition and Subtraction operators.

Loops over the values.

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.

OverflowError, cannot convert float infinity to integer.

The above expression is evaluated as 16%15//16, which is equal to 1//16, which results in 0.

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

eval can be used as a variable.

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 built in function vars() returns a dictionary containing all the variables that exist in the place. Hence the output of the code shown above is: {‘a’ : ‘hello’, ‘q’ : 10, ……..plus built-in names set by Python….}

Tuples are represented with round brackets.

The given number is -122. Here the total number of digits (including the negative sign) should be 6 according to the expression. In addition to this, there is a negative sign in the given print expression. Hence the output will be −−00122.

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.