Code_1.ipynb

Kernel: Python 3

Check to see if you're ready to go on Thursday!

1. Run each block of code

2. Check for errors

3. When you think you're error free, flag down a teaching team member to confirm!

###This is what an error looks like
print(a)

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-1-7fe2d780de59> in <module>()
      1 ###This is what an error looks like
----> 2 print(a)

NameError: name 'a' is not defined

Objectives

Get comfortable with IPython Notebook

• How to start IPython Notebook

• How to read data into pandas

• How to do simple manipulations on pandas dataframes

Start a notebook:

For each class, we'll be using a set of common data science libraries and tools, like the IPython notebook. You can start an IPython notebook by running

jupyter notebook $NAME_OF_FILE

Try it yourself!

Read and run the block of code below by:

1. Clicking on it and pressing the play button above or

2. Using a short cut- (help --> keyboard shortcuts)

%matplotlib inline
import matplotlib.pyplot as plt
import matplotlib as mpl
import pandas as pd

mpl.rcParams['figure.figsize'] = (15, 6)
pd.set_option('display.width', 4000)
pd.set_option('display.max_columns', 100)

First: Read in the data

Review Simple Commands

Practice downloading and reading into sample data

# Download and read the data (this may take more than 1 minute)
orig_data = pd.read_csv('../../assets/dataset/311-service-requests.csv', parse_dates=['Created Date'], low_memory=False)

plt.scatter(orig_data['Longitude'], orig_data['Latitude'], marker='.', color="purple")

<matplotlib.collections.PathCollection at 0x925de80>

Try this Example:

Graph the number of noise complaints each hour in New York

complaints = orig_data[['Created Date', 'Complaint Type']]
noise_complaints = complaints[complaints['Complaint Type'] == 'Noise - Street/Sidewalk']
noise_complaints.set_index('Created Date').sort_index().resample('H', how=len).plot()

C:\Users\ystrano\AppData\Local\Continuum\anaconda3\lib\site-packages\ipykernel_launcher.py:3: FutureWarning: how in .resample() is deprecated
the new syntax is .resample(...)..apply(<func>)
  This is separate from the ipykernel package so we can avoid doing imports until

<matplotlib.axes._subplots.AxesSubplot at 0x9428da0>

Second: Using IPython

Review Python Basics

Test your skills by answering the following questions:

Question 1. Divide 10 by 20 and set the result to a variable named "A"

A = 10/20
print(A)

0.5

#### If you did not get a float (decimals) alter your equation to get the desired result (0.5) 
A = 10.0/20
print(A)

0.5

Question 2. Create a function called division that will divide any two numbers and prints the result (with decimals).

Call your function. Confirm that the results are as expected.

def division(numerator, denominator):
    result = float(numerator) / denominator
    print(result)
division(20, 10)
division(10, 20)

2.0
0.5

Question 3. Using .split() split my string into separate words

my_string = "the cow jumped over the moon"
words = my_string.split()
# returns ['the', 'cow', 'jumped', 'over', 'the', 'moon']
print(words)

['the', 'cow', 'jumped', 'over', 'the', 'moon']

Question 4. How many words are in my_string?

word_count = len(words)
#returns the number of words- 6
print(word_count)

6

Question 5. Use a list comprehension to find the length of each word

length_of_each_word = [len(x) for x in words]
print(length_of_each_word)

[3, 3, 6, 4, 3, 4]

Question 6. Put the words back together in a variable called sentence using .join()

# put them back together with join
sentence = ' '.join(words)
print(sentence)

the cow jumped over the moon

Bonus: Add a "||" between each word

# the " " puts the space in between the words. or you could put anything else in
alternate_sentence = '||'.join(words)
print(alternate_sentence)

the||cow||jumped||over||the||moon