OAU CSC 201 Practice Quiz

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

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

The formatting method {1:<10} represents the second positional argument, left justified in a 10 character wide field.

Lists should be copied by executing [:] operation.

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’.

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.

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

The line of code shown above can be simplified to state that ‘hello’ should be printed if the argument passed to the Boolean function amounts to zero, else ‘morning’ will be printed.

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).

The function len() returns the length of the number of elements in the iterable. Therefore the output of the function shown above is 4.

The loop is entered twice.

Any odd number on being AND-ed with 1 always gives 1. Any even number on being AND-ed with this value always gives 0.

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’.

The \n adds a new line.

List data type can store any values within it.

All of the operators shown above have associativity from left to right, except exponentiation operator (**) which has its associativity from right to left.

Tuples are represented with round brackets.

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

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).

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

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

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.

Execute help(math.trunc) to get details.

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 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.

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.

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

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

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

eval can be used as a variable.

Error, objects of type int aren’t iterable.

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.

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’)

Suppose we have an expression ~A. This is evaluated as: -A – 1. Therefore, the expression ~100 is evaluated as -100 – 1, which is equal to -101.

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.

Python shell throws a NoneType object back.

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.

in is a keyword.

^ is the Binary XOR operator.

The result of the expression shown above is (6.0, 16.0). This is because the result is automatically rounded off to one decimal place.

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

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

Within the subject string, curly braces designate substitution targets and arguments to be inserted either by position or keyword. Hence the output of the code shown above:’hello, good,and morning’.

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.

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.

[::-1] reverses the string.