Functions

3. Where is function defined? a) Module b) Class c) Another function d) All of the mentioned

Answer: d Explanation: Functions can be defined inside a module, a class or another function.

1. Python supports the creation of anonymous functions at runtime, using a construct called __________ a) Lambda b) pi c) anonymous d) None of the mentioned

Answer: a Explanation: Python supports the creation of anonymous functions (i.e. functions that are not bound to a name) at runtime, using a construct called lambda. Lambda functions are restricted to a single expression. They can be used wherever normal functions can be used.

8. What is the output of the below program? def C2F(c): return c * 9/5 + 32 print C2F(100) print C2F(0) a) 212 32 b) 314 24 c) 567 98 d) None of the mentioned

Answer: a Explanation: The code shown above is used to convert a temperature in degree celsius to fahrenheit.

7. What is the output of below program? def cube(x): return x * x * x x = cube(3) print x a) 9 b) 3 c) 27 d) 30

Answer: c Explanation: A function is created to do a specific task. Often there is a result from such a task. The return keyword is used to return values from a function. A function may or may not return a value. If a function does not have a return keyword, it will send a none value.

3. What is the output of the following code? i=0 def change(i): i=i+1 return i change(1) print(i) a) 1 b) Nothing is displayed c) 0 d) An exception is thrown

Answer: c Explanation: Any change made in to an immutable data type in a function isn't reflected outside the function.

4. What is the output of the below program? def printMax(a, b): if a > b: print(a, 'is maximum') elif a == b: print(a, 'is equal to', b) else: print(b, 'is maximum') printMax(3, 4) a) 3 b) 4 c) 4 is maximum d) None of the mentioned

Answer: c Explanation: Here, we define a function called printMax that uses two parameters called a and b. We find out the greater number using a simple if..else statement and then print the bigger number.

7. What is the output of below program? def f(x, y, z): return x + y + z f(2, 30, 400) a) 432 b) 24000 c) 430 d) No output

Answer: a Explanation: None.

6. Which of the following refers to mathematical function? a) sqrt b) rhombus c) add d) rhombus

Answer: a Explanation: Functions that are always available for usage, functions that are contained within external modules, which must be imported and functions defined by a programmer with the def keyword. Eg: math import sqrt A sqrt() function is imported from the math module.

5. Which of the following is the use of id() function in python? a) Id returns the identity of the object b) Every object doesn't have a unique id c) All of the mentioned d) None of the mentioned

Answer: a Explanation: Each object in Python has a unique id. The id() function returns the object's id.

7. What is the output of below program? def say(message, times = 1): print(message * times) say('Hello') say('World', 5) a) Hello WorldWorldWorldWorldWorld b) Hello World 5 c) Hello World,World,World,World,World d) Hello HelloHelloHelloHelloHello

Answer: a Explanation: For some functions, you may want to make some parameters optional and use default values in case the user does not want to provide values for them. This is done with the help of default argument values. You can specify default argument values for parameters by appending to the parameter name in the function definition the assignment operator (=) followed by the default value. The function named say is used to print a string as many times as specified. If we don't supply a value, then by default, the string is printed just once. We achieve this by specifying a default argument value of 1 to the parameter times. In the first usage of say, we supply only the string and it prints the string once. In the second usage of say, we supply both the string and an argument 5 stating that we want to say the string message 5 times.

3. What is the output of the below program? def sayHello(): print('Hello World!') sayHello() sayHello() a) Hello World! Hello World! b) 'Hello World!' 'Hello World!' c) Hello Hello d) None of the mentioned

Answer: a Explanation: Functions are defined using the def keyword. After this keyword comes an identifier name for the function, followed by a pair of parentheses which may enclose some names of variables, and by the final colon that ends the line. Next follows the block of statements that are part of this function. def sayHello(): print('Hello World!') # block belonging to the function # End of function # sayHello() # call the function sayHello() # call the function again

1. Which of the following is the use of function in python? a) Functions are reusable pieces of programs b) Functions don't provide better modularity for your application c) you can't also create your own functions d) All of the mentioned

Answer: a Explanation: 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.

5. What is the output of the below program ? x = 50 def func(x): print('x is', x) x = 2 print('Changed local x to', x) func(x) print('x is now', x) a) x is now 50 b) x is now 2 c) x is now 100 d) None of the mentioned

Answer: a Explanation: The first time that we print the value of the name x with the first line in the function's body, Python uses the value of the parameter declared in the main block, above the function definition. Next, we assign the value 2 to x. The name x is local to our function. So, when we change the value of x in the function, the x defined in the main block remains unaffected. With the last print function call, we display the value of x as defined in the main block, thereby confirming that it is actually unaffected by the local assignment within the previously called function.

2. What is the output of this program? y = 6 z = lambda x: x * y print z(8) a) 48 b) 14 c) 64 d) None of the mentioned

Answer: a Explanation: The lambda keyword creates an anonymous function. The x is a parameter, that is passed to the lambda function. The parameter is followed by a colon character. The code next to the colon is the expression that is executed, when the lambda function is called. The lambda function is assigned to the z variable. The lambda function is executed. The number 8 is passed to the anonymous function and it returns 48 as the result. Note that z is not a name for this function. It is only a variable to which the anonymous function was assigned.

9. What is the output of the following code? def display(b, n): while n > 0: print(b,end="") n=n-1 display('z',3) a) zzz b) zz c) An exception is executed d) Infinite loop

Answer: a Explanation: The loop runs three times and 'z' is printed each time.

5. What is the output of the following code? a=10 b=20 def change(): global b a=45 b=56 change() print(a) print(b) a)10 56 b)45 56 c)10 20 d)Syntax Error

Answer: a Explanation: The statement "global b" allows the global value of b to be accessed and changed. Whereas the variable a is local and hence the change isn't reflected outside the function.

10. What is the output of the below program? def sum(*args): '''Function returns the sum of all values''' r = 0 for i in args: r += i return r print sum.__doc__ print sum(1, 2, 3) print sum(1, 2, 3, 4, 5) a) 6 15 b) 6 100 c) 123 12345 d) None of the mentioned

Answer: a Explanation: We use the * operator to indicate, that the function will accept arbitrary number of arguments. The sum() function will return the sum of all arguments. The first string in the function body is called the function documentation string. It is used to document the function. The string must be in triple quotes.

6. Lambda contains block of statements a) True b) False

Answer: b

2. What are the two main types of functions? a) Custom function b) Built-in function & User defined function c) User function d) System function

Answer: b Explanation: 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.

8. What is the output of below program? def writer(): title = 'Sir' name = (lambda x:title + ' ' + x) return name who = writer() who('Arthur') a) Arthur Sir b) Sir Arthur c) Arthur d) None of the mentioned

Answer: b Explanation: None.

4. What is the output of the following piece of code? def a(b): b = b + [5] c = [1, 2, 3, 4] a(c) print(len(c)) a) 4 b) 5 c) 1 d) An exception is thrown

Answer: b Explanation: Since a list is mutable, any change made in the list in the function is reflected outside the function.

9. What is the output of the below program? def power(x, y=2): r = 1 for i in range(y): r = r * x return r print power(3) print power(3, 3) a) 212 32 b) 9 27 c) 567 98 d) None of the mentioned

Answer: b Explanation: The arguments in Python functions may have implicit values. An implicit value is used, if no value is provided. Here we created a power function. The function has one argument with an implicit value. We can call the function with one or two arguments.

6. What is the output of the below program? x = 50 def func(): global x print('x is', x) x = 2 print('Changed global x to', x) func() print('Value of x is', x) a) x is 50 Changed global x to 2 Value of x is 50 b) x is 50 Changed global x to 2 Value of x is 2 c) x is 50 Changed global x to 50 Value of x is 50 d) None of the mentioned

Answer: b Explanation: The global statement is used to declare that x is a global variable - hence, when we assign a value to x inside the function, that change is reflected when we use the value of x in the main block.

9. What is the output of below program? def maximum(x, y): if x > y: return x elif x == y: return 'The numbers are equal' else: return y print(maximum(2, 3)) a) 2 b) 3 c) The numbers are equal d) None of the mentioned

Answer: b Explanation: The maximum function returns the maximum of the parameters, in this case the numbers supplied to the function. It uses a simple if..else statement to find the greater value and then returns that value.

7. What is the output of the following code? def change(one, *two): print(type(two)) change(1,2,3,4) a) Integer b) Tuple c) Dictionary d) An exception is thrown

Answer: b Explanation: The parameter two is a variable parameter and consists of (2,3,4). Hence the data type is tuple.

1. What is a variable defined outside a function referred to as? a) A static variable b) A global variable c) A local variable d) An automatic variable

Answer: b Explanation: The value of a variable defined outside all function definitions is referred to as a global variable and can be used by multiple functions of the program.

4. Does Lambda contains return statements? a) True b) False

Answer: b Explanation: lambda definition does not include a return statement. it always contains an expression which is returned. Also note that we can put a lambda definition anywhere a function is expected. We don't have to assign it to a variable at all.

5. Lambda is a statement. a) True b) False

Answer: b Explanation: lambda is an anonymous function in Python. Hence this statement is false.

8. If a function doesn't have a return statement, which of the following does the function return? a) int b) null c) None d) An exception is thrown without the return statement

Answer: c Explanation: A function can exist without a return statement and returns None if the function doesn't have a return statement.

8. What is the output of the below program? def func(a, b=5, c=10): print('a is', a, 'and b is', b, 'and c is', c) func(3, 7) func(25, c = 24) func(c = 50, a = 100) a) a is 7 and b is 3 and c is 10 a is 25 and b is 5 and c is 24 a is 5 and b is 100 and c is 50 b) a is 3 and b is 7 and c is 10 a is 5 and b is 25 and c is 24 a is 50 and b is 100 and c is 5 c) a is 3 and b is 7 and c is 10 a is 25 and b is 5 and c is 24 a is 100 and b is 5 and c is 50 d) None of the mentioned

Answer: c Explanation: If you have some functions with many parameters and you want to specify only some of them, then you can give values for such parameters by naming them - this is called keyword arguments - we use the name (keyword) instead of the position (which we have been using all along) to specify the arguments to the function. The function named func has one parameter without a default argument value, followed by two parameters with default argument values. In the first usage, func(3, 7), the parameter a gets the value 3, the parameter b gets the value 7 and c gets the default value of 10. In the second usage func(25, c=24), the variable a gets the value of 25 due to the position of the argument. Then, the parameter c gets the value of 24 due to naming i.e. keyword arguments. The variable b gets the default value of 5. In the third usage func(c=50, a=100), we use keyword arguments for all specified values. Notice that we are specifying the value for parameter c before that for a even though a is defined before c in the function definition.

10. What is the output of this program? min = (lambda x, y: x if x < y else y) min(101*99, 102*98) a) 9997 b) 9999 c) 9996 d) None of the mentioned

Answer: c Explanation: None.

2. Which keyword is use for function? a) Fun b) Define c) Def d) Function

Answer: c Explanation: None.

3. What is the output of below program? lamb = lambda x: x ** 3 print(lamb(5)) a) 15 b) 555 c) 125 d) None of the mentioned

Answer: c Explanation: None.

9. What is the output of this program? L = [lambda x: x ** 2, lambda x: x ** 3, lambda x: x ** 4] for f in L: print(f(3)) a) 27 81 343 b) 6 9 12 c) 9 27 81 d) None of the mentioned

Answer: c Explanation: None.

2. What is a variable defined inside a function referred to as? a) A global variable b) A volatile variable c) A local variable d) An automatic variable

Answer: c Explanation: The variable inside a function is called as local variable and the variable definition is confined only to that function.

10. What is the output of the following piece of code? def find(a, **b): print(type(b)) find('letters',A='1',B='2') a) String b) Tuple c) Dictionary d) An exception is thrown

Answer: c Explanation: b combines the remaining parameters into a dictionary.

1. Which are the advantages of functions in python? a) Reducing duplication of code b) Decomposing complex problems into simpler pieces c) Improving clarity of the code d) All of the mentioned

Answer: d

4. What is called when a function is defined inside a class? a) Module b) Class c) Another function d) Method

Answer: d

10. Which of the following is a features of DocString? a) Provide a convenient way of associating documentation with Python modules, functions, classes, and methods b) All functions should have a docstring c) Docstrings can be accessed by the __doc__ attribute on objects d) All of the mentioned

Answer: d Explanation: 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.

6. What is the output of the following code? def change(i = 1, j = 2): i = i + j j = j + 1 print(i, j) change(j = 1, i = 2) a) An exception is thrown because of conflicting values b) 1 2 c) 3 3 d) 3 2

Answer: d Explanation: The values given during function call is taken into consideration, that is, i=2 and j=1.