Python Introduction: Control Flow

for loops in Python always iterate over something list-like:

for i in range(3,10):

    print(i)
    
    

3
4
5
6
7
8
9

Note that Python does block-structuring by leading spaces.

Also note the trailing ":".

---

if/else are as you would expect them to be:

for i in range(10):
    if i % 3 == 0:
        print("{0} is divisible by 3".format(i))
    else:
        print("{0} is not divisible by 3".format(i))

print("My name is %s" % 'Luke')
print("My name is {}".format('Luke'))

while loops exist too:

i = 0
while True:
    i += 1
    if i**3 + i**2 + i + 1 == 3616:
        break

print("SOLUTION:", i)

---

Building lists by hand can be a little long. For example, build a list of the squares of integers below 50 divisible by 7:

mylist = []

for i in range(50):

    if i % 7 == 0:

        mylist.append(i**2)

mylist

Python has a something called list comprehension:

mylist = [i**2 for i in range(50) if i % 7 == 0]
print(mylist)

[0, 49, 196, 441, 784, 1225, 1764, 2401]

Dictionaries

#mydict = {key: value}
mydict = {'Luke': 15,'Mariana' : 22}
print(mydict["Mariana"])

22

string = "Batman"
mydict = {key:ord(key) for key in string}

print(mydict)