Python Tutorial: Strings Datatype

Data stored in memory can of different types and Python like other languages have different standard data types. Sometime back we did a post on Python Numbers. Today we will be covering other standard datatypes i.e. Strings.

Note: All examples shown in the post are based on python3.

Like other languages, python also has the same meaning/definition for Strings. They are a contiguous set of characters enclosed within single/double quotation marks

strA = "Hello "
strB = 'World!'

#Printing the above variables on screen

print strA #This will work in Python2
print strB #This will work in Python2

print( strA ) #This will work in Python3
print( strB ) #This will work in Python3

Result of above Python3 Code

String Slicing:

Strings can be sliced i.e. subsets of a string, using the slice operator ([:] or []). The index starts from 0.


print( strA[0] )   #prints the first character of variable strA
print( strA[1:3] ) #prints characters from first index to third
print( strA[3:] )  #prints characters from third index

String Concatenation:

Like other languages python also provides the functionality to concatenate strings. It is done its the + operator


print( "Print Concatenated Output: " + strA + strB )

Code Output
If you try to concat another datatype using + operator, you would get an error "cannot convert 'int' object to str implicitly". So to achieve that we have two ways:

1. We can do by putting values using a comma inside print()
2. Other way, we can use an inbuilt function str(). This will convert any datatype to string thus, allowing us to use + operator


print( strA + 4 ) #This will give an error as mentioned above

#Correct Way to Concat String and another Datatype

print( strA, 4 ) #Method 1
print( strA + str(1234) ) #Method 2

Escape Characters:

The definition an escape character is a character which invokes an alternative interpretation on subsequent characters in a character sequence. It can be interpreted in a single as well as double quoted string.

Below is the list of escape characters with their description:

Some of the special operators

We only saw the + operator, but apart from this there are many others. Below is the list of all operators:

Formatting Operator

Formatting Operator %, is one of the features which reminded me of the time when I used to write code in C. Here in python it functions the same way:

Below is a list of formatting operators:



"""You can have multiple formatting operators, but remember the sequence of variables must be followed after % inside a bracket () separated by comma"""

num = 2
post_num = 129

print( "Code %s Learn" %num) 

print( "Code %s Learn\'s post number: %s" %(num,post_num))

String Formatting Example Output

You must have noticed that I have used Triple quotes in the above example. Triple quote is used for writing multi-line comments, whereas # is used for writing a single line comment.

Python also provides multiple built-in functions for String manipulations. Below is the gist of some functions:

Check Python Docs for detailed reference.


Install Python on Mac

Mac by default comes with a Python 2.7 installed, but if you want to install latest version of Python, it can be down easily.

We will need to follow the below steps:

Step 1: You can either go to Python website and download the latest stable release. (Or just click here).

Step 2: Open the installer and instal Python on your Mac.

Step 3: Open Terminal and check the versions of the python that is came pre-installed by python --version. If this gives you a result of python 2.7.6 (2.7.*) then don't worry, we are not done yet.

Step 4: In your terminal if you type python, it will run the pre-installed version i.e. 2.7.*. To make our newly installed python we will have to type python3. We can make the terminal start Python 3, just by doing aliasing.

Step 5: On your terminal type open ~/.bash_profile. If this gives a "Not Found" error, just make the file by typing: touch ~/.bash_profile. This will create the file.

Step 6: After the file is created, copy the text
 alias python="python3"

Step 7: We are not done yet. To make the changes take effect, type the following in your terminal source ~/.bash_profile. This will apply the changes you made in your file.

Step 8: You are done!! Type python on terminal and let us know :)


Informatics : The Future

Informatics, a new term/concept for people. Many people who stay in Europe know this term "Informatics" as a synonym to Computer Science. Like myself when I was thinking to do a Master's from Europe, I found that universities where I was looking to go didn't have Computer Science instead they Master's in Informatics.

This term for parents all over the world is very new and parents are very sceptical about sending their son/daughter or even getting themselves a degree in Informatics. With this post hopefully the picture will be cleared and will help students/professional to look at it in a different aspect.

What does Informatics means?

If we go by the traditional definition that we see on the search engines is the Science of Information. But for me:

Informatics stands as the term DTP where D is Data, T is Technology and P is People i.e. combination of all three. Its where computing (which we learn from computer science) is done with respect to another domain. 

With the above diagram, it seems clear that, Data which is generated by us is transformed by developers/analysts using technology in such a way that it can help people solve a problem or make a the world a better place to live.

Informatics offered by:

There are a lot of Universities offering degree in Informatics in the United States of America, below are a few:

1. University of Southern California
2. Indiana University
3. University of Michigan
4. University of Washington
5. UC Irvine
6. Carnegie Mellon University
7. Georgia Tech
8. Rutgers
9. Penn State

Informatics is not just restricted to Computers field, it has application in Medical, Retail, Social Networking, Health, Ocean, Sports etc.

Roles offered after degree:

Informatics as mentioned above has its application in various field so depending on the course and field you undertake the roles vary.

But for Informatics (General) the common roles are:

- Data Scientist
- Data Analyst
- Analyst
- Information Architects
- Software Engineers
- Hadoop Expert
- Interaction Designers, to name a few.

Future of Informatics:

The future of Informatics is very bright as the data being generated in every field is increasing every second, the roles and jobs are proportionally increasing and getting more diverse and niche.

Below is an image which explains how and why of data being generated:

Infographic is from Domo, a data visualizing firm.
At last I would like to say,  in our world we might not be aware of what power and meaning data has hidden in it. But I feel lucky to come across some real-life examples where data with use of technology and people is making a difference. Just for an example : West Ham Football Club (a Football club in the famous English Premier League) Manager Sam Allardyce uses footballing data and then buys players accordingly and so far if we see West Ham current season, it's turning out that the knowledge offered to him on recruiting is turning out to be a success.