Add changes to Variables lesson

Author: kochaika

Variables/Arithmetic operators/arithmetic_operators.py

@@ -1,16 +1,16 @@
-number = 9.0        # Float number
+init_number = 9.0        # Float number
 
-division_result = number / 2
+division_result = init_number / 2
 
-division_remainder = number % 2
+division_remainder = init_number % 2
 
 multiplication_result = division_result * 2
 
 addition_result = multiplication_result + division_remainder
 
-subtraction_result = number - multiplication_result
+subtraction_result = init_number - multiplication_result
 
-floor_result = number // 2
+floor_result = init_number // 2
 
 power_result = multiplication_result ** 3
 

Variables/Arithmetic operators/task-info.yaml

@@ -1,29 +1,29 @@
 type: edu
 files:
-- name: arithmetic_operators.py
-  visible: true
-  placeholders:
-  - offset: 54
-    length: 10
-    placeholder_text: '# divide the number by two'
-  - offset: 87
-    length: 10
-    placeholder_text: '# get the remainder of the division of the number by two'
-  - offset: 123
-    length: 19
-    placeholder_text: '# multiply the division result by 2'
-  - offset: 162
-    length: 42
-    placeholder_text: '# add the division remainder to the multiplication result'
-  - offset: 227
-    length: 30
-    placeholder_text: '# subtract the multiplication result from the initial number'
-  - offset: 274
-    length: 11
-    placeholder_text: '# perform a floor division of number by 2'
-  - offset: 302
-    length: 26
-    placeholder_text: '# raise the multiplication result to the power of 3'
-- name: tests/test_task.py
-  visible: false
-feedback_link: https://docs.google.com/forms/d/e/1FAIpQLSfRlDlldKfuq-cHMNFfHMER61P1PRIan7KG6yp1GvaweDI7GA/viewform?usp=pp_url&entry.2103429047=Variables+/+Arithmetic+Operators
+  - name: arithmetic_operators.py
+    visible: true
+    placeholders:
+      - offset: 59
+        length: 15
+        placeholder_text: '# divide the init_number by 2'
+      - offset: 97
+        length: 15
+        placeholder_text: '# get the remainder of the division of the init_number by 2'
+      - offset: 138
+        length: 19
+        placeholder_text: '# multiply the division_result by 2'
+      - offset: 177
+        length: 42
+        placeholder_text: '# add the division_remainder to the multiplication_result'
+      - offset: 242
+        length: 35
+        placeholder_text: '# subtract the multiplication_result from the init_number'
+      - offset: 294
+        length: 16
+        placeholder_text: '# perform a floor division of init_number by 2'
+      - offset: 327
+        length: 26
+        placeholder_text: '# raise the multiplication_result to the power of 3'
+  - name: tests/test_task.py
+    visible: false
+feedback_link: https://docs.google.com/forms/d/e/1FAIpQLSfRlDlldKfuq-cHMNFfHMER61P1PRIan7KG6yp1GvaweDI7GA/viewform?usp=pp_url&entry.2103429047=Variables+/+Arithmetic+Operators

Variables/Arithmetic operators/task.md

@@ -17,17 +17,29 @@ either both be numbers, or one argument must be an integer and the other – a s
 
 - The `-` (subtraction) operator yields the difference of its arguments.
 
+For example
+```python
+a = 16
+b = 3
+result = a // b  # result will be 5
+result = a % b   # result will be 1
+result = a ** 2  # result will be 256 (16 in power of 2)
+```
+
 The binary arithmetic operations have the conventional priority levels. Note that 
 some of these operations also apply to certain non-numeric types.
 
 You can read more on this topic <a href="https://docs.python.org/3/reference/expressions.html#binary-arithmetic-operations">here</a>.
+
+For more structured and detailed information, you can also refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/5865).
+
 ### Task
- - Divide the value stored in `number` by `2`.
+ - Divide the value stored in `init_number` by `2`.
  - Calculate a remainder of such a division.
- - Multiply the division result by `2`.
- - Add the division remainder to the multiplication result.
- - Subtract the multiplication result from the number.
- - Perform a floor division of `number` by 2.
+ - Multiply the `division_result` by `2`.
+ - Add the `division_remainder` to the `multiplication_result`.
+ - Subtract the `multiplication_result` from the `init_number`.
+ - Perform a floor division of `init_number` by 2.
  - Raise the `multiplication_result` to the power of 3
 
 <div class='hint'>First, use the <code>/</code> operator.</div>
@@ -38,3 +50,7 @@ You can read more on this topic <a href="https://docs.python.org/3/reference/exp
 <div class='hint'>Then use the <code>+</code> operator.</div>
 
 <div class='hint'>Then use the <code>-</code> operator.</div>
+
+<div class='hint'>Then use the <code>//</code> operator.</div>
+
+<div class='hint'>Then use the <code>**</code> operator.</div>

Variables/Boolean operators/task.md

@@ -3,6 +3,8 @@
 Boolean is a type of value that can only be `True` or `False`. The `==` (equality) operator 
 compares two variables and checks whether they are equal. You will learn more about boolean operators in a later [task](course://Condition expressions/Boolean operators). 
 
+For more structured and detailed information, you can refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/6025).
+
 ### Task
  - Check whether the variable `two` is equal to `three`.
  - Check if the variable `is_equal` has a deceiving name.

Variables/Comparison operators/task.md

@@ -22,6 +22,9 @@ that of any arithmetic, shifting or bitwise operation. Comparisons yield boolean
 values: either `True` or `False`. Comparisons can be chained arbitrarily, and 
 expressions like `a < b < c` have the 
 conventional mathematical meaning. Read more on comparisons <a href="https://docs.python.org/3/reference/expressions.html#comparisons">here</a>.
+
+For more structured and detailed information, you can also refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/5920).
+
 ### Task
  - Check whether the value of the variable `three` is strictly greater than the value of 
 the variable `two`.

Variables/Type conversion/task.md

@@ -3,7 +3,10 @@
 There are several built-in functions that let you convert one data type into another. 
 These functions return a new object representing the converted value. `int(x)` 
 converts `x` into an integer. `float(x)` converts `x` into a floating-point number. `str(x)` 
-converts object `x` into a string representation.  
+converts object `x` into a string representation.
+
+For more structured and detailed information, you can refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/6224).
+
 ### Task
 Convert `float_number` into an integer.  
 

Variables/Undefined variable/task.md

@@ -4,10 +4,9 @@ Variable names may only contain Latin letters, digits, and/or the underscore
 character, and they cannot start with a digit. They also cannot be any of the 
 reserved <a href="https://docs.python.org/3/reference/lexical_analysis.html#keywords">keywords</a>.
 ### Task
-Check what happens if you use a variable which is not defined yet. Change and run the code in the editor – try to print out an undefined name.  
+Check what happens if you use a variable which is not defined yet. Change and run the code in the editor – try to print out an **undefined** name (i.e. type the name of an undefined variable inside the brackets of the `print` statement).  
 This should cause an exception - a `NameError`.
 
 Note, that "check" command only runs the testing system, and you will not see the output, so you need to run the file.
 
-<div class="hint">Type the name of an undefined variable inside the brackets of the <code>print</code> statement. 
-Note that variable names must start with a letter and can contain only letters, '_', and numbers.</div>
+<div class="hint">for example, try to print <code>var1</code> variable instead of <code>variable</code></div>

Variables/Variable definition/task-info.yaml

@@ -1,17 +1,17 @@
 type: edu
 files:
-- name: variable_definition.py
-  visible: true
-  placeholders:
-  - offset: 231
-    length: 1
-    placeholder_text: ???
-  - offset: 337
-    length: 1
-    placeholder_text: '# Assign a new value'
-  - offset: 472
-    length: 5
-    placeholder_text: '# Assign 2 to both a and b here'
-- name: tests/test_task.py
-  visible: false
+  - name: variable_definition.py
+    visible: true
+    placeholders:
+      - offset: 227
+        length: 1
+        placeholder_text: ???
+      - offset: 320
+        length: 10
+        placeholder_text: '# Assign a new value'
+      - offset: 445
+        length: 5
+        placeholder_text: '# Assign 2 to both a and b here'
+  - name: tests/test_task.py
+    visible: false
 feedback_link: https://docs.google.com/forms/d/e/1FAIpQLSfRlDlldKfuq-cHMNFfHMER61P1PRIan7KG6yp1GvaweDI7GA/viewform?usp=pp_url&entry.2103429047=Variables+/+Variable+Definition

Variables/Variable definition/task.md

@@ -3,9 +3,13 @@
 Variables are used to store values so we can refer to them later. A variable 
 is like a label, and in Python we use the ' `=` ' symbol, known as the 
 assignment operator, to assign a value to a variable. An assignment can be 
-chained, e.g., `a = b = 2`.   
+chained, e.g., `a = b = 2`.  
+
+For more structured and detailed information, you can refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/5859).
+
 ### Task
- - Change the value stored in the variable `greetings`.
- - Use the chain assignment to store 2 in both `a` and `b` on line 15.
+ 1. Assign `World` string to `name` variable 
+ 2. On line 10 change the value in the `name` variable with your actual name.
+ 3. Use the chain assignment to store 2 in both `a` and `b` on line 15.
 
-<div class="hint">Type a new value in the answer placeholder.</div>
+<div class="hint">Type a new "name" variable value in the answer placeholder.</div>

Variables/Variable definition/tests/test_task.py

@@ -27,16 +27,7 @@ def setUp(self):
                       "errors and warnings.".format(str(e)))
 
     def test_assignment_operator(self):
-        expected_first_greetings = "greetings = greetings"
-        actual_output = self.actualOutput.getvalue()
-
-        self.assertIn(expected_first_greetings, actual_output, msg="The line expressing greetings after the initial "
-                                                                   "assignment was not found. Check that the variable is "
-                                                                   "assigned properly and that the print statement "
-                                                                   "is intact.")
-
-    def test_assignment_operator2(self):
-        expected_first_greetings = "greetings = greetings"
+        expected_first_greetings = "Hello, World"
         actual_output = self.actualOutput.getvalue()
 
         self.assertIn(expected_first_greetings, actual_output, msg="The line expressing greetings after the initial "
@@ -45,16 +36,16 @@ def test_assignment_operator2(self):
                                                                    "is intact.")
 
     def test_variable(self):
-        unexpected_greetings = "greetings"
+        unexpected_name = "World"
 
         try:
-            actual_greetings = try_import().greetings
+            actual_name = try_import().name
         except AttributeError:
-            self.fail(msg="The variable greetings seems to be undefined. Do not remove it from the task code.")
+            self.fail(msg="The variable name seems to be undefined. Do not remove it from the task code.")
 
-        self.assertNotEqual(unexpected_greetings, actual_greetings, msg="The variable greetings doesn't seem to be "
-                                                                        "reassigned. You should change it to something "
-                                                                        "else.")
+        self.assertNotEqual(unexpected_name, actual_name, msg="The variable name doesn't seem to be "
+                                                              "reassigned. You should change it to something "
+                                                              "else.")
 
     def test_chained_assignment(self):
         expected_a = expected_b = 2

Variables/Variable definition/variable_definition.py

@@ -3,15 +3,15 @@
 # For now: it is used to convert the variable "a" into a string.
 print("a = " + str(a))
 
-# Assign "greetings" to the variable using the assignment operator
-greetings = "greetings"
-print("greetings = " + str(greetings))
-# Reassign anything to the variable here
-greetings = 5
-print("greetings = " + str(greetings))
+# Assign "World" to the name variable using the assignment operator
+name = "World"
+print("Hello, " + str(name))
+# Reassign name variable with your actual name
+name = "Username"
+print("Hello, " + str(name))
 
 
-# This is called a "chained assignment". It assigns the value 2 to variables "a" and "b".
+# Use here the chain assignment to assigns the value 2 to variables "a" and "b".
 a = b = 2
 print("a = " + str(a))
 print("b = " + str(b))

Variables/Variable types/task.md

@@ -21,6 +21,8 @@ and an `int` is a number without a decimal point.
 For more information on this topic, refer to the "<a href="https://docs.python.org/3/reference/datamodel.html#objects-values-and-types">Objects, values and types</a>"
 and "<a href="https://docs.python.org/3/reference/datamodel.html#the-standard-type-hierarchy">The standard type hierarchy</a>" sections in Python Documentation.
 
+For more structured and detailed information, you can also refer to [this Hyperskill knowledge base page](https://hyperskill.org/learn/step/5852).
+
 ### Task
 Print the type of the variable `float_number`.