**TEALS Program**
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# Lab 3.04 - Aliasing & Scope
## In Your notebook
### Aliasing
1. Will updating `b` affect `a`? Explain why or why not.
```python
a = [1, 2, 4]
b = a
```
2. Predict what `my_list` list will print out when this code is run. If you are not sure, test the code by copying and running it.
```python
# input: a list of ints
# output: an int
def update_list(a_list):
a_list[3] = "yo"
b = a_list[4]
b = 100
my_list = [1, 2, 3, 4, 5]
update_list(my_list)
print(my_list)
```
### Scope
1. Draw a stack diagram for the following:
```python
var_1 = "kittens"
var_2 = "cookies"
# input: a string
# output: a string
def my_function(my_favorite_things):
song_lyrics = "raindrops on roses, "
combined_song = song_lyrics + my_favorite_things
return combined_song
# input: a string
# output: a string
def my_function_2(item, item2):
full_lyrics = item + " on " + item2
full_song = my_function(full_lyrics)
return full_song
my_song = my_function_2(var_1, var_2)
```
## Complete the following on your own:
1. Write down what (if anything) is wrong with the following code.
2. If there is an issue, write out how to fix it.
3. If you are unsure, copy and run the code and fix it
### Problem 1
```python
var_1 = 'cat'
var_2 = 'dog'
def print_out_my_favorite(favorite_pet):
if favorite_pet == var_1:
print("My favorite pet is the cat.")
if favorite_pet == var_2:
print("My favorite pet is the dog.")
var_1 = 'dog'
var_2 = "cat"
print_out_my_favorite(var_1)
print("var_1:" + var_1 + " var_2:" + var_2)
```
### Problem 2
```python
var_1 = 'cat'
var_2 = 'dog'
def print_out_my_favorite(favorite_pet):
var_1 = 'dog'
var_2 = 'cat'
if favorite_pet == var_1:
print("My favorite pet is the cat.")
if favorite_pet == var_2:
print("My favorite pet is the dog.")
print_out_my_favorite(var_1)
print("var_1:" + var_1 + " var_2:" + var_2)
```
### Problem 3
```python
var_1 = 'cat'
var_2 = 'dog'
def print_out_my_favorite(favorite_pet):
if favorite_pet == var_1:
print("My favorite pet is the cat.")
if favorite_pet == var_2:
print("My favorite pet is the dog.")
print_out_my_favorite(var_1)
print("var_1:" + var_1 + " var_2:" + var_2)
```
## In your console
### Write a program using the following specifications:
1. Program includes a global variable, `my_num`.
2. Create three functions that update `my_num`
3. `add2`: this function adds 2 to `my_num`
4. `multiply_num`: this function takes in a parameter, `multiplier`, and multiplies `my_num` by that parameter
5. `add2_and_multiply`: this function takes in a parameter, `multiplier`, and calls `add2`, then calls `multiply_num`.
### Complete the program
Write the following code in the main part of the program:
1. set `my_num` to some initial value you choose
2. print `my_num`
3. call `add2_and_multiply()` with some argument you choose
4. print the final value of `my_num`
5. Confirm that the printed values match what you expected