OAU CSC 201 Practice Quiz

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

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

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.

[::-1] reverses the string.

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

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.

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

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.

[::-1] reverses the list.

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]’.

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

In the code shown above, the decorator helps us to prefix the dollar sign along with the value. Since the second argument is zero, the output of the code is: $100.

Dictionary stores values in terms of keys and values.

Case is always significant while dealing with identifiers in python.

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.

Loops over the keys of the dictionary.

Execute help(math.trunc) to get details.

Within the subject string, curly braces represent substitution targets and arguments to be inserted. Hence the output of the code shown above:
‘hello, world, universe’.

l (or L) stands for long.

Tuples are represented with round brackets.

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.

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.

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

+’ cannot be converted to a float.

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.

The \n adds a new line.

All of the above examples show explicit conversion. However the expression int(’10.8’) results in an error.

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

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

The def keyword is used to create, (or define) a function in python.

Execute help(round) in the shell to get details of the parameters that are passed into the round function.

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

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

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’.

Class is a user-defined data type.

Variable x is incremented and printed twice.

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 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.

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

The first letter of the string is converted to uppercase and the others are converted to lowercase.

OverflowError, cannot convert float infinity to integer.

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.

Loops over the elements of the set and prints them.