Python Summary Test 2 (Chapter 4-5)

A data structure described as LIFO is actually a:

stack

The top‑most Python exception is named:

BaseException

The following code print('Mike' > "Mikey") prints:

False

What will be the output of the following code? class A: A = 1 print(hasattr(A,'A'))

True

A predefined Python variable, storing the current module name, is called:

__name__

UTF‑8 is:

a form of encoding Unicode code points

isalnum ( ) checks if a string contains only letters and digits, and this is:

a method

A code point is:

a number which makes up a character

When a file is opened in read mode, it:

it must exist (an exception will be raised otherwise)

The unnamed except: block:

must be the last one

Which of the following is true

packages can contain modules

ASCII is:

short for American Standard Code for Information Interchange

Which of the approachable EXPECT branches is taken into consideration when the exception occurs

the first matching

The following code x = '\'' print(len(x)) prints:

1

The two basic, mutually exclusive, file open modes are named:

binary and text

The pyc file contains:

compiled Python code

The += operator, when applied to string, performs:

concatenation

The following code print(3 * 'abc' + 'xyz') prints:

abcabcabcxyz

How does the readline() method react when the end‑of‑file occurs?

it returns an empty string

A user defines exception:

may be derived from the Exception class

Knowing that a function named fun() resides in a module named mod, and it has been imported using the following line: import mod choose the way it can be invoked in your code:

mod.fun()

The following code: print(ord('c') - ord('a')) prints:

2

The readlines() method returns a:

list

Assuming that the open() invocation has gone successfully, the following snippet will: for x in open('file','rt'): print(x)

read the file line by line

A method able to read data from file into a byte array object, is name:

readinto()

If you want to fill a byte array with data read in from a stream, you use the:

readinto() method

Entering the try: block implies that:

some of the instructions from this block may not be executed

An assertion can be used to:

stop the program when some data have improper values

The byte array class can create objects which are designed to:

store amorphic data organized in bytes

The strerror function comes from the OS module, and it's designed to:

translate an error number into an error description

The following statement: assert var == 0

will stop the program when var == 0

The following code print(chr(ord('z') - 2)) prints:

x

A function returning a list of all entities available in a module is called:

dir()

The following statement: from a.b import c causes the import of:

entity c from module b from package a

What will be the result of executing the following code? class A: def __init__(self): pass a = A(1) print(hasattr(a,'A'))

it will raise an exception

The sys.stdin stream is normally associated with a:

keyboard

A subclass is usually:

more specialized than its superclass

An object is characterized by the following three:

name, properties, activities

If the class's constructor is declared as below, which one of the assignments is valid? class Class: def __init__(self): pass

object = Class()

When an exception occurs, we say that it has been:

raised

The expression: 'mike' > 'Mike'

is True

UNICODE is a standard:

like ASCII, but much more expansive

What will be the output of the following code? class A: def __init__(self,v = 1): self.v = v def set(self,v): self.v = v return v a = A() print(a.set(a.v + 1))

2

What will be the output of the following code? class A: X = 0 def __init__(self,v = 0): self.Y = v A.X += v a = A() b = A(1) c = A(2) print(c.X)

3

A namespace is:

a space in which names exists

The function named super() may be used to:

access super class's attributes and/or methods

A variable existing as a separate being in separate object is called:

an instance variable

When a module is imported, its contents:

are executed once (implicitly)

If you want to open a text file in append mode, you would use the following mode string:

at

If you want to import pi from math, you'd use:

from math import pi

Knowing that a function named fun() resides in a module named mod, choose the proper way to import it:

from mod import fun

A function able to check if an object is equipped with a given property is name:

hasattr()

What will be the result of executing the following code? def o(p): def q(): return '*' * p return q r = o(1) s = o(2) print(r() + s())

it will print ****

What will be the result of executing the following code? def I(n): s = '+' for i in range(n): s += s yield s for x in I(2): print(x,end='')

it will print ++++++

What will be the result of executing the following code? class A: v = 2 class B(A): v = 1 class C(B): pass o = C() print(o.v)

it will print 1

What will be the result of executing the following code? try: raise Exception(1,2,3) except Exception as e: print(len(e.args))

it will print 3

What will be the result of executing the following code? class A: pass class B(A): pass class C(B): pass print(issubclass(C,A))

it will print True

What will be the result of executing the following code? class I: def __init__(self): self.s = 'abc' self.i = 0 def __iter__(self): return self def __next__(self): if self.i == len(self.s): raise StopIteration v = self.s[self.i] self.i += 1 return v for x in I(): print(x,end='')

it will print abc

What will be the result of executing the following code? def I(): s = 'abcdef' for c in s[::2]: yield c for x in I(): print(x,end='')

it will print ace

Is there a way to check if a class is a subclass of another class?

yes, there is a function able to do that

An alternative name for a data structure called a stack is:

LIFO

The following code: print(float("1,3"))

raises a ValueError exception

If s is a stream opened in read mode, the following line q = s.read(1) will:

read 1 character from the stream

If there is a superclass named A and a subclass named B, which one of the presented invocations should you put instead of a comment? class A: def __init__(self): self.a = 1 class B: def __init__(self): # put selected line here self.a = 2

A.__init__(self)

What will be the result of executing the following code? class A: def __str__(self): return 'a' class B(A): def __str__(self): return 'b' class C(B): pass o = C() print(o)

it will print b

What will be the result of executing the following code? class A: def a(self): print('a') class B: def a(self): print('b') class C(B,A): def c(self): self.a() o = C() o.c()

it will print b

What will be the result of executing the following code? def f(x): try: x = x / x except: print("a",end='') else: print("b",end='') finally: print("c",end='') f(1) f(0)

it will print bcac

What will be the result of executing the following code? class Ex(Exception): def __init__(self,msg): Exception.__init__(self,msg + msg) self.args = (msg,) try: raise Ex('ex') except Ex as e: print(e) except Exception as e: print(e)

it will print ex

What will be the effect of running the following code? class A: def __init__(self,v): self.__a = v + 1 a = A(0) print(a.__a)

it will raise an AttributeError exception