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

# # Loops and Conditionals 
# 
# ### Other resources
# 
# Python course at https://codecademy.com
# 
# Python flow control tutorial https://docs.python.org/3/tutorial/controlflow.html 

# ## Loops

# The `range()` command offers an easy way to loop over a sequence of numbers.  Remember that Python is 0 indexed.

# In[1]:


for i in range(10):
    print(i)


# We can also loop over anything that is iterable, this includes lists, tuples, and dictonaries.

# In[2]:


alist = ['a', 'b', 'c']


# In the loop below `aletter` takes on each value of `alist` every cycle through the loop.

# In[3]:


for aletter in alist:
    print(aletter)


# There are also `while`-loops, but the syntax is not as clear as `for`-loops and there is always a danger of entering an infinite loop.

# In[4]:


i=0
mybool = False
while mybool is not True:
    print(i)
    i += 1
    if i > 10:
        mybool = True


# I prefer `for`-loops with a fixed number of iterations and a `break` statement to replicate the logic of `while`-loops, but protecting from infinite cycles.

# In[5]:


for i in range(100):
    print(i)
    
    if i > 10:
        break


# Here is an example of a conditional statement with `and` or `or` logic.

# In[6]:


for i in range(100):
    
    if i < 10 or i > 20:
        print(i)
    else:
        print("Hello!")


# Python offers a clean syntax for testing if an item is stored in a list, tuple, or dictionary.

# In[7]:


alist = ['a', 'b', 'c']

if 'd' not in alist:
    print("True!!!!")
else:
    print("False!!!!")