02-more-syntax

Python

Some new syntax

Intro

As we've noted, Python and Javascript are functionally identical for the most part (except that Python CANNOT be used client-side). That being said, there are significant differences in their syntax.

Take note of some of the topics below.

• Note: Python's convention is to separate words using an underscore instead of camelCase. For example, a variable would look like this in Python: joe_shmoe, as opposed to joeShmoe

Dictonaries

In Python, objects are called dictionaries. Other than the name though, the behave much.

The following is an example of a dictionary in Python:

    user =	{
      "name": "Joe Shmoe",
      "job": "software",
      "age": 36,
      "children": ["Ricky", "Bobby", "Bob", "Dylan"]
    }

You can also initialize an object to null values like so:

user = dict.fromkeys(["name", "job", "age", "children"])

A dictionary, just like an object, is simply a set of key/value pairs.

Loops

Python has for loops just like javascript, only with some syntactic diffrences.

For one thing (pun intended), we don't need parentheses or curly braces. Instead, we use a colon at the end of the condition, and simply indent the code to be executed (in other words, what would be in curlies in javascript).

warriors = ["curry", "durant", "thompson", "green", "iguodala", "cousins"]

for i in warriors:
  print(i + " plays on the best team in the NBA")

Iterating through an object looks a little different:

    user =	{
      "name": "Joe Shmoe",
      "job": "software",
      "age": 36
    }
    for key, value in user.items():
        print('your {0} is {1}.'.format(key, value))

We use the items method to let the loop know that we are iteration through an object.

We use the format method to let the loop know what we are refering to when we print the above string.

Notice too that we did not use a closing tag of any sort. It is the indentation (or lack thereof) on the next line that takes care of that.

Finally, let's take a look at the while loop in Python.

One way to get out of a while loop is to meet the condition we initialized it with, but that is not the only way. There are two key words to remember: break and continue. Break will back us out of the loop, while continue re-executes the code before it.

count = 1

while count < 10:
  print(count)
  if count == 5:
    print("buzz")
  if count == 9:
    break  
  count+=1

Conditionals

You can see an example of conditionals in the while loop above. It's pretty straightforward, and even uses less code than javascript.

name = "Kevin"
if name == "Kevin":
  print("Hart")
else:
  print("I don't know that guy.")  

Instructions

In this exercise, we'll be practicing Python syntax topic-by-topic.

Navigate to prompt.py, and follow the instructions therein.