OAU CSC 201 Practice Quiz

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.

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.

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

The code shown above returns the number of times a given function has been called. Hence the output of this code is: 3

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.

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 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.

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]’.

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

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.

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

Loops over the values.

// 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.

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

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

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.

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

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

Class is a user-defined data type.

The code shown above converts the given arguments to hexadecimal and decimal values and prints the result. This is done using the format specifiers %x and %d respectively. Hence the output of the code shown above is: ‘ff, 255’.

Tuples are represented with round brackets.

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

9 isn’t allowed in an octal number.

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.

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.

The code shown above rounds the floating point value to two decimal places. In this code, a variety of addition formatting features such as zero padding, total field width etc. Hence the output of this code is: ‘3.35 | 03.35 | +003.3’.

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 first prints the word “Decorated” and then “ordinary”. Hence the output of this code is:
Decorated
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).

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).

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

The expression shown above rounds off the given number to the number of decimal places specified. Since the expression given specifies rounding off to two decimal places, the output of this expression will be 56.24. Had the value been x=56.234 (last digit being any number less than 5), the output would have been 56.23.

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.

The code shown above shows a general decorator which can work with any number of arguments.

range(0) is empty

Causes a KeyError.

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

A folder of python programs is called as a package of modules.

We use the function append to add an element to the list.

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

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 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.

[::-1] reverses the list.

This is a built-in function which rounds a number to give precision in decimal digits. In the above case, since the number of decimal places has not been specified, the decimal number is rounded off to a whole number. Hence the output will be 5.

[::-1] reverses the list.

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

String formatting also allows conversion targets on the left to refer to the keys in a dictionary coded on the right and fetch the corresponding values. In the code shown above, (qty) and (food) in the format string on the left refers to keys in the dictionary literal on the right and fetch their assorted values. Hence the output of the code shown above is: 1 more spam.

i is not in x[1:].