OAU CSC 201 Practice Quiz

Execute help(id) to find out details in python shell.id returns a integer value that is unique.Execute help(id) to find out details in python shell.id returns a integer value that is unique.

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.

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

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”.

in is a keyword.

Objects of type set have no attribute values.

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

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

// 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.

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

l (or L) stands for long.

We can simply convert strings with a %s format expression or the str built-in function. Both of these methods have been shown in this code. Hence the output is: ) (‘3.3456789’, ‘3.3456789’)

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.

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,),).

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

In python, power operator is x**y i.e. 2**3=8.

^ is the XOR operator. The binary form of 4 is 0100 and that of 12 is 1100. Therefore, 0100^1100 is 1000, which is equal to 8.

Loops over the keys of the dictionary.

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’].

Carefully look at the colons.

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

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

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.

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.

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 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.

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

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).

“i” is not in “abcdef”.

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 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.

Variable names can be of any length.

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

Case is always significant while dealing with identifiers in python.

Class is a user-defined data type.

The function max() is being used to find the maximum value from among -3, -4 and false. Since false amounts to the value zero, hence we are left with min(0, 2, 7) Hence the output is 0 (false).

In the code shown above, the function mk() is the decorator. The function which is getting decorated is mk2(). The return function is given the name p().

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

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’.

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.

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

NameError, i is not defined.

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