#!/usr/bin/env python
# coding: utf-8

# # Introduction To Python

# This is a collection of various statements, features, etc. of IPython and the Python language.  Much of this content is taken from other notebooks so I can't take credit for it, I just extracted the highlights I felt were most useful.
# 
# Code cells are run by pressing shift-enter or using the play button in the toolbar.

# In[1]:


a = 10


# In[2]:


print(a)


# In[3]:


import math


# In[4]:


x = math.cos(2 * math.pi)
print(x)


# Import the whole module into the current namespace instead.

# In[5]:


from math import *
x = cos(2 * pi)
print(x)


# Several ways to look at documentation for a module.

# In[6]:


print(dir(math))


# In[7]:


help(math.cos)


# ### Variables

# In[8]:


x = 1.0
type(x)


# In[9]:


# dynamically typed
x = 1
type(x)


# ### Operators

# In[10]:


1 + 2, 1 - 2, 1 * 2, 1 / 2


# In[11]:


# integer division of float numbers
3.0 // 2.0


# In[12]:


# power operator
2 ** 2


# In[13]:


True and False


# In[14]:


not False


# In[15]:


True or False


# In[16]:


2 > 1, 2 < 1, 2 > 2, 2 < 2, 2 >= 2, 2 <= 2


# In[17]:


# equality
[1,2] == [1,2]


# ### Strings

# In[18]:


s = "Hello world"
type(s)


# In[19]:


len(s)


# In[20]:


s2 = s.replace("world", "test")
print(s2)


# In[21]:


s[0]


# In[22]:


s[0:5]


# In[23]:


s[6:]


# In[24]:


s[:]


# In[25]:


# define step size of 2
s[::2]


# In[26]:


# automatically adds a space
print("str1", "str2", "str3")


# In[27]:


# C-style formatting
print("value = %f" % 1.0) 


# In[28]:


# alternative, more intuitive way of formatting a string 
s3 = 'value1 = {0}, value2 = {1}'.format(3.1415, 1.5)
print(s3)


# ### Lists

# In[29]:


l = [1,2,3,4]

print(type(l))
print(l)


# In[30]:


print(l[1:3])
print(l[::2])


# In[31]:


l[0]


# In[32]:


# don't have to be the same type
l = [1, 'a', 1.0, 1-1j]
print(l)


# In[33]:


start = 10
stop = 30
step = 2
range(start, stop, step)

# consume the iterator created by range
list(range(start, stop, step))


# In[34]:


# create a new empty list
l = []

# add an elements using `append`
l.append("A")
l.append("d")
l.append("d")

print(l)


# In[35]:


l[1:3] = ["b", "c"]
print(l)


# In[36]:


l.insert(0, "i")
l.insert(1, "n")
l.insert(2, "s")
l.insert(3, "e")
l.insert(4, "r")
l.insert(5, "t")

print(l)


# In[37]:


l.remove("A")
print(l)


# In[38]:


del l[7]
del l[6]

print(l)


# ### Tuples

# In[39]:


point = (10, 20)
print(point, type(point))


# In[40]:


# unpacking
x, y = point

print("x =", x)
print("y =", y)


# ### Dictionaries

# In[41]:


params = {"parameter1" : 1.0,
          "parameter2" : 2.0,
          "parameter3" : 3.0,}

print(type(params))
print(params)


# In[42]:


params["parameter1"] = "A"
params["parameter2"] = "B"

# add a new entry
params["parameter4"] = "D"

print("parameter1 = " + str(params["parameter1"]))
print("parameter2 = " + str(params["parameter2"]))
print("parameter3 = " + str(params["parameter3"]))
print("parameter4 = " + str(params["parameter4"]))


# ### Control Flow

# In[43]:


statement1 = False
statement2 = False

if statement1:
    print("statement1 is True")
elif statement2:
    print("statement2 is True")
else:
    print("statement1 and statement2 are False")


# ### Loops

# In[44]:


for x in range(4):
    print(x)


# In[45]:


for word in ["scientific", "computing", "with", "python"]:
    print(word)


# In[46]:


for key, value in params.items():
    print(key + " = " + str(value))


# In[47]:


for idx, x in enumerate(range(-3,3)):
    print(idx, x)


# In[48]:


l1 = [x**2 for x in range(0,5)]
print(l1)


# In[49]:


i = 0
while i < 5:
    print(i)
    i = i + 1
print("done")


# ### Functions

# In[50]:


# include a docstring
def func(s):
    """
    Print a string 's' and tell how many characters it has    
    """
    
    print(s + " has " + str(len(s)) + " characters")


# In[51]:


help(func)


# In[52]:


func("test")


# In[53]:


def square(x):
    return x ** 2


# In[54]:


square(5)


# In[55]:


# multiple return values
def powers(x):
    return x ** 2, x ** 3, x ** 4


# In[56]:


powers(5)


# In[57]:


x2, x3, x4 = powers(5)
print(x3)


# In[58]:


f1 = lambda x: x**2
f1(5)


# In[59]:


map(lambda x: x**2, range(-3,4))


# In[60]:


# convert iterator to list
list(map(lambda x: x**2, range(-3,4)))


# ### Classes

# In[61]:


class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        
    def translate(self, dx, dy):
        self.x += dx
        self.y += dy
        
    def __str__(self):
        return("Point at [%f, %f]" % (self.x, self.y))


# In[62]:


p1 = Point(0, 0)
print(p1)


# In[63]:


p2 = Point(1, 1)

p1.translate(0.25, 1.5)

print(p1)
print(p2)


# ### Exceptions

# In[64]:


try:
    print(test)
except:
    print("Caught an expection")


# In[65]:


try:
    print(test)
except Exception as e:
    print("Caught an exception: " + str(e))