diff --git a/README.md b/README.md
index 4377f33..e0f40a8 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,6 @@
 - [Comprehensive topic-wise list of Machine Learning and Deep Learning tutorials, codes, articles and other resources](https://github.com/ujjwalkarn/Machine-Learning-Tutorials/blob/master/README.md).
 
 ## The Python Language
-- [Learn Python Codecademy](https://www.codecademy.com/learn/python#)
 - [Python 3 in one picture](https://fossbytes.com/wp-content/uploads/2015/09/python-3-in-one-pic.png)
 - [**Awesome Python**](https://github.com/vinta/awesome-python)
 - [**Jargon from the functional programming world in simple terms!**](https://github.com/hemanth/functional-programming-jargon)
@@ -26,6 +25,13 @@
     - [Scripting with Python](https://www.schrodinger.com//AcrobatFile.php?type=supportdocs&type2=&ident=404)
     - [**Can I use Python as a bash replacement?**](http://stackoverflow.com/questions/209470/can-i-use-python-as-a-bash-replacement)
 
+## Useful Online Courses
+- [Learn Python (Codecademy)](https://www.codecademy.com/learn/python#)
+- [Free Interactive Course: Intro to Python for Data Science (DataCamp)](https://www.datacamp.com/courses/intro-to-python-for-data-science)
+- [Introduction to Computer Science and Programming Using Python (MIT)](https://www.edx.org/course/introduction-computer-science-mitx-6-00-1x-11)
+- [Python for Everybody](https://www.coursera.org/learn/python)
+- [Python Programming Essentials](https://www.coursera.org/learn/python-programming)
+
 ## Data Science with Python
 - [**Data Science IPython Notebooks**](https://github.com/donnemartin/data-science-ipython-notebooks)
 - [Awesome Python - Data Analysis](https://github.com/vinta/awesome-python#science-and-data-analysis)
@@ -46,7 +52,6 @@
 - [**Which is better for data analysis: R or Python?**](https://www.quora.com/Which-is-better-for-data-analysis-R-or-Python)
 - [**Web scraping in Python**](https://github.com/ujjwalkarn/Web-Scraping)
 - [The Guide to Learning Python for Data Science](http://www.datasciencecentral.com/profiles/blogs/the-guide-to-learning-python-for-data-science-2)
-- [Free Interactive Course: Intro to Python for Data Science](https://www.datacamp.com/courses/intro-to-python-for-data-science)
 - [Python For Data Science - A Cheat Sheet For Beginners](https://www.datacamp.com/community/tutorials/python-data-science-cheat-sheet-basics)
 - [Top voted Python data science questions](http://datascience.stackexchange.com/questions/tagged/python)
 - [Awesome Python - Data Visualization](https://github.com/vinta/awesome-python#data-visualization)
@@ -196,6 +201,7 @@
 - [NLP Tutorial with Python](http://www.datasciencecentral.com/profiles/blogs/python-nlp-tools)
 
 ## Sentiment Analysis with Python
+- [A Comprehensive Guide to Sentiment Analysis](https://monkeylearn.com/sentiment-analysis/)
 - [Twitter-Sentiment-Analysis](https://github.com/ujjwalkarn/Twitter-Sentiment-Analysis)
 - [Basic Sentiment Analysis with Python](http://fjavieralba.com/basic-sentiment-analysis-with-python.html)
 - [What is the best way to do Sentiment Analysis with Python?](https://www.quora.com/What-is-the-best-way-to-do-Sentiment-Analysis-with-Python-1)
diff --git a/Twitter-Data-Analysis/extract_twitter_data.py b/Twitter-Data-Analysis/extract_twitter_data.py
index b2558dd..178df35 100644
--- a/Twitter-Data-Analysis/extract_twitter_data.py
+++ b/Twitter-Data-Analysis/extract_twitter_data.py
@@ -28,7 +28,7 @@ class MyListener(StreamListener):
  
     def on_data(self, data):
         try:
-            with open('C:\\Users\\ujjwal.karn\\Desktop\\Tweets\\python.json', 'a') as f:  #change location here
+            with open('location/file_name.txt', 'a') as f:  #change location here
                 f.write(data)
                 return True
         except BaseException as e:
diff --git a/basic_commands.py b/basic_commands.py
index b15d929..8c401fc 100644
--- a/basic_commands.py
+++ b/basic_commands.py
@@ -1,5 +1,5 @@
 >>> a = ['a', 'b', 'c', 'd', 'e']
->>> for index, item in enumerate(a): print index, item
+>>> for index, item in enumerate(a): print index, item # enumerate function will generate an index for the item + item it self. 
 ...
 0 a
 1 b
@@ -37,6 +37,7 @@
 str1 = "this is string example....wow!!!";
 str2 = "exam";
 
+# find function will print the position for the first character of the string if it's found!
 print str1.find(str2);
 print str1.find(str2, 10);
 print str1.find(str2, 40);