Concatenation

Concatenation simply means to join. Python supports joining strings together with the addition operator + (pretty cool right?).

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str1 = "Q-"
str2 = "Programming"
concatenated = str1+str2
print(concatenated)

Q-Programming

Keep in mind that since whitespace is counted as a character, concatenation will not result in the creation of whitespaces between words, unless specified beforehand.

Let's look at the next two code blocks to see how.

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word1 = "Hello"
word2 = "World"
print(word1 + word2)

HelloWorld

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word1 = "Hello "
word2 = "World"
print(word1 + word2)

Hello World

As you can see in the second block, we left a space after "Hello". This space is counted as a character and hence we get the output "Hello World"

Repetition

Python allows users to repeat srings using the * operator. They must always be multiplied by a positive integer.

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word = "QP"
print(word * 5)

QPQPQPQPQP

Membership

Python has two membership operators in and not in. As the names suggest, these are used to check whether a character or set of characters is in a particular string or not. The final result will be a Boolean - either True or False.

Example of in:

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"H" in "Hello"

True

Example of not in:

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"H" not in "Hello"

False

Slicing

Slicing is used to extract certain sections of a string, through specifying an index range and step value.

You know what indices are, but what is a step value? Simply put, a step value is the difference between the integer values of indices. For example, if the index range is 0:8 and the step value is 2, the program will access every second character of the string i.e. 0,2,4,6

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string = "Q-Programming"
print(string[2:10])
print(string[2:10:3])
print(string[-2:-10:-2])

Programm
Pgm
nmag