if-elif-else

if <condition>:
       <if body>
elif <second_condition>:
       <elif body>
elif <third_condition>:
       <elif body>
...
else:
       <else body>

Conditionally execute code. The elif and else blocks are optional.

Components:

if <condition>:

If the condition is True, the body of the if statement is executed. Condition will be checked even if another if condition is fulfilled.

elif <condition>:

If the if condition is False, code moves onto the elif statement and checks the condition. If an if statement was executed, the elif conditions will not be checked.

else <condition>:

If none of the if and elif conditions are met, the else body will execute.

---

pets = bpd.read_csv('pets.csv')
pets

Index	ID	Species	Color	Weight	Age
0	dog_001	dog	black	40	5
1	cat_001	cat	golden	1.5	0.2
2	cat_002	cat	black	15	9
3	dog_002	dog	white	80	2
4	dog_003	dog	black	25	0.5
5	ham_001	hamster	black	1	3
6	ham_002	hamster	golden	0.25	0.2
7	cat_003	cat	black	10	0

def more_descriptive_name(id_str, species, color, weight, age):
    return id_str + ': This ' + color + ' ' + species + ' weighs ' + weight + ' lbs and is ' + age + ' years old'
    
def cat_and_dog_info(pet_id):
    id_arr = np.array(pets.get('ID'))
    if pet_id not in id_arr:
        return 'This pet is not in our record'
    pets_info = pets[pets.get('ID') == pet_id]
    age = pets_info.get('Age').iloc[0]
    weight = pets_info.get('Weight').iloc[0]
    species = pets_info.get('Species').iloc[0]
    color = pets_info.get('Color').iloc[0]
    if (species == 'dog') and (age < 1.5):
        return pet_id + ': This is a puppy 🐶'
    elif (species == 'cat') and (age < 1):
        return pet_id + ': This is a kitten 🐱'
    elif (species == 'dog') or (species == 'cat'):
        weight = str(weight)
        age = str(age)
        return more_descriptive_name(pet_id, species, color, weight, age)
        
    else:
        return pet_id + ': This pet is not a dog or a cat'

cat_and_dog_info('dog_001')

'dog_001: This black dog weighs 40.0 lbs and is 5.0 years old'

cat_and_dog_info('cat_001')

'cat_001: This is a kitten 🐱'

cat_and_dog_info('cat_009')

'This pet is not in our record'