Showing posts with label cx_Oracle. Show all posts
Showing posts with label cx_Oracle. Show all posts

Monday, June 18, 2018

Twitter Analytics using Python - Part 3

This is my third (of five) post on using Python to process Twitter data.

Check out my all the posts in the series.

In this post I'll have a quick look at how to save the tweets you have download. By doing this allows you to access them at a later point and to perform more analysis. You have a few instances of saving the tweets. The first of these is to save them to files and the second option is to save them to a table in a database.

Saving Tweets to files

In the previous blog post (in this series) I had converged the tweets to Pandas and then used the panda structure to perform some analysis on the data and create some charts. We have a very simple command to save to CSV.

# save tweets to a file
tweets_pd.to_csv('/Users/brendan.tierney/Dropbox/tweets.csv', sep=',')

We can inspect this file using a spreadsheet or some other app that can read CSV files and get the following.

Twitter app8

When you want to read these tweets back into your Python environment, all you need to do is the following.

# and if we want to reuse these tweets at a later time we can reload them
old_tweets = pd.read_csv('/Users/brendan.tierney/Dropbox/tweets.csv')

old_tweets

Tweet app9

That's all very easy!


Saving Tweets to a Database

There are two ways to add tweets to table in the database. There is the slow way (row-by-row) or the fast way doing a bulk insert.

Before we get started with inserting data, lets get our database connection setup and the table to store the tweets for our date. To do this we need to use the cx_oracle python library. The following codes shows the setting up of the connections details (without my actual login details), establishes the connects and then retrieves some basic connection details to prove we are connected.

# import the Oracle Python library
import cx_Oracle

# define the login details
p_username = "..."
p_password = "..."
p_host = "..."
p_service = "..."
p_port = "1521"

# create the connection
con = cx_Oracle.connect(user=p_username, password=p_password, dsn=p_host+"/"+p_service+":"+p_port)
cur = con.cursor()

# print some details about the connection and the library
print("Database version:", con.version)
print("Oracle Python version:", cx_Oracle.version)


Database version: 12.1.0.1.0
Oracle Python version: 6.3.1

Now we can create a table based on the current date.

# drop the table if it already exists
#drop_table = "DROP TABLE TWEETS_" + cur_date
#cur.execute(drop_table)

cre_table = "CREATE TABLE TWEETS_" + cur_date + " (tweet_id number, screen_name varchar2(100), place varchar2(2000), lang varchar2(20), date_created varchar2(40), fav_count number, retweet_count number, tweet_text varchar2(200))"

cur.execute(cre_table)

Now lets first start with the slow (row-by-row) approach. To do this we need to take our Panda data frame and convert it to lists that can be indexed individually.

lst_tweet_id = [item[0] for item in rows3]
lst_screen_name = [item[1] for item in rows3]
lst_lang =[item[3] for item in rows3]
lst_date_created = [item[4] for item in rows3]
lst_fav_count = [item[5] for item in rows3]
lst_retweet_count = [item[6] for item in rows3]
lst_tweet_text = [item[7] for item in rows3]

#define a cursor to use for the the inserts
cur = con.cursor()
for i in range(len(rows3)):
    #do the insert using the index. This can be very slow and should not be used on big data
    cur3.execute("insert into TWEETS_2018_06_12 (tweet_id, screen_name, lang, date_created, fav_count, retweet_count, tweet_text) values (:arg_1, :arg_2, :arg_3, :arg_4, :arg_5, :arg_6, :arg_7)",
                 {'arg_1':lst_tweet_id[i], 'arg_2':lst_screen_name[i], 'arg_3':lst_lang[i], 'arg_4':lst_date_created[i],
                  'arg_5':lst_fav_count[i], 'arg_6':lst_retweet_count[i], 'arg_7':lst_tweet_text[i]})

#commit the records to the database and close the cursor
con.commit()
cur.close()

Tweet app10

Now let us look a quicker way of doing this.

WARNING: It depends on the version of the cx_oracle library you are using. You may encounter some errors relating to the use of floats, etc. You might need to play around with the different versions of the library until you get the one that works for you. Or these issues might be fixed in the most recent versions.

The first step is to convert the panda data frame into a list.

rows = [tuple(x) for x in tweets_pd.values]
rows

Tweet app11

Now we can do some cursor setup like setting the array size. This determines how many records are sent to the database in each batch. Better to have a larger number than a single digit number.

cur = con.cursor()

cur.bindarraysize = 100

cur2.executemany("insert into TWEETS_2018_06_12 (tweet_id, screen_name, place, lang, date_created, fav_count, retweet_count, tweet_text) values (:1, :2, :3, :4, :5, :6, :7, :8)", rows)

Check out the other blog posts in this series of Twitter Analytics using Python.

Tuesday, February 13, 2018

Oracle and Python setup with cx_Oracle

Is Python the new R?

Maybe, maybe not, but that I'm finding in recent months is more companies are asking me to use Python instead of R for some of my work.

In this blog post I will walk through the steps of setting up the Oracle driver for Python, called cx_Oracle. The documentation for this drive is good and detailed with plenty of examples available on GitHub. Hopefully there isn't anything new in this post, but it is my experiences and what I did.

1. Install Oracle Client
The Python driver requires Oracle Client software to be installed. Go here, download and install. It's a straightforward install. Make sure the directories are added to the search path.

2. Download and install cx_Oracle
You can use pip3 to do this.
 
pip3 install cx_Oracle

Collecting cx_Oracle
  Downloading cx_Oracle-6.1.tar.gz (232kB)
    100% |████████████████████████████████| 235kB 679kB/s
Building wheels for collected packages: cx-Oracle
  Running setup.py bdist_wheel for cx-Oracle ... done
  Stored in directory: /Users/brendan.tierney/Library/Caches/pip/wheels/0d/c4/b5/5a4d976432f3b045c3f019cbf6b5ba202b1cc4a36406c6c453
Successfully built cx-Oracle
Installing collected packages: cx-Oracle
Successfully installed cx-Oracle-6.1  

3. Create a connection in Python
Now we can create a connection. When you see some text enclosed in angled brackets <>, you will need to enter your detailed for your schema and database server.
 
# import the Oracle Python library
import cx_Oracle

# define the login details
p_username = ""
p_password = ""
p_host = ""
p_service = ""
p_port = "1521"

# create the connection
con = cx_Oracle.connect(user=p_username, password=p_password, dsn=p_host+"/"+p_service+":"+p_port)

# an alternative way to create the connection
# con = cx_Oracle.connect('/@/:1521')

# print some details about the connection and the library
print("Database version:", con.version)
print("Oracle Python version:", cx_Oracle.version)


Database version: 12.1.0.1.0
Oracle Python version: 6.1

4. Query some data and return results to Python
In this example the query returns the list of tables in the schema.
 
# define a cursor to use with the connection
cur = con.cursor()
# execute a query returning the results to the cursor
cur.execute('select table_name from user_tables')
# for each row returned to the cursor, print the record
for row in cur:
    print("Table: ", row)

Table:  ('DECISION_TREE_MODEL_SETTINGS',)
Table:  ('INSUR_CUST_LTV_SAMPLE',)
Table:  ('ODMR_CARS_DATA',)

Now list the Views available in the schema.
 
# define a second cursor
cur2 = con.cursor()
# return the list of Views in the schema to the cursor
cur2.execute('select view_name from user_views')
# display the list of Views
for result_name in cur2:
    print("View: ", result_name)

View:  ('MINING_DATA_APPLY_V',)
View:  ('MINING_DATA_BUILD_V',)
View:  ('MINING_DATA_TEST_V',)
View:  ('MINING_DATA_TEXT_APPLY_V',)
View:  ('MINING_DATA_TEXT_BUILD_V',)
View:  ('MINING_DATA_TEXT_TEST_V',)

5. Query some data and return to a Panda in Python
Pandas are commonly used for storing, structuring and processing data in Python, using a data frame format. The following returns the results from a query and stores the results in a panda.
 
# in this example the results of a query are loaded into a Panda
# load the pandas library
import pandas as pd

# execute the query and return results into the panda called df
df = pd.read_sql_query("SELECT * from INSUR_CUST_LTV_SAMPLE", con)

# print the records returned by query and stored in panda
print(df.head())

 CUSTOMER_ID     LAST    FIRST STATE     REGION SEX    PROFESSION  \
0     CU13388     LEIF   ARNOLD    MI    Midwest   M        PROF-2   
1     CU13386     ALVA   VERNON    OK    Midwest   M       PROF-18   
2      CU6607   HECTOR  SUMMERS    MI    Midwest   M  Veterinarian   
3      CU7331  PATRICK  GARRETT    CA       West   M       PROF-46   
4      CU2624  CAITLYN     LOVE    NY  NorthEast   F      Clerical   

  BUY_INSURANCE  AGE  HAS_CHILDREN   ...     MONTHLY_CHECKS_WRITTEN  \
0            No   70             0   ...                          0   
1            No   24             0   ...                          9   
2            No   30             1   ...                          2   
3            No   43             0   ...                          4   
4            No   27             1   ...                          4   

   MORTGAGE_AMOUNT  N_TRANS_ATM  N_MORTGAGES  N_TRANS_TELLER  \
0                0            3            0               0   
1             3000            4            1               1   
2              980            4            1               3   
3                0            2            0               1   
4             5000            4            1               2   

  CREDIT_CARD_LIMITS  N_TRANS_KIOSK  N_TRANS_WEB_BANK       LTV  LTV_BIN  
0               2500              1                 0  17621.00   MEDIUM  
1               2500              1               450  22183.00     HIGH  
2                500              1               250  18805.25   MEDIUM  
3                800              1                 0  22574.75     HIGH  
4               3000              2              1500  17217.25   MEDIUM  

[5 rows x 31 columns]

6. Wrapping it up and closing things
Finally we need to wrap thing up and close our cursors and our connection to the database.
 
# close the cursors
cur2.close()
cur.close()

# close the connection to the database
con.close()

Useful links
cx_Oracle website
cx_Oracle documentation
cx_Oracle examples on GitHub

Watch out for more blog posts on using Python with Oracle, Oracle Data Mining and Oracle R Enterprise.