Python 3a - Data Types
Data Types in Python
If you are a Computer Science student you need to know about the different data types that are used in programming.
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​String – A sequence of alphanumeric characters (e.g. “Hello!” or “Toy Story 4” or “Boeing 747”)
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Integer – A whole number (e.g. 1470 or 0 or -34)
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Float (also called Real) – A decimal number (e.g. -32.12 or 3.14)
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Boolean – A logical operation (True or False)
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Character – A single alphanumeric character (e.g. “a” or “6” or “?”) [Not used in Python as it would just be a string with a length of 1]
Converting to Another Data Type
Converting a variable from one data type to another is called casting.
Casting Commands
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str(variable_name) converts a variable to a string.
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int(variable_name) converts a variable to a integer.
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float(variable_name) converts a variable to a float (decimal number).
An integer (or float) value may be cast into a string so that it can be used with + as part of a sentence to avoid spaces.
total = 45
print("You owe £" , total , "in total.")
print("You owe £" + str(total) , "in total.")
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You owe £ 45 in total.
You owe £45 in total.
When dividing an integer the answer is automatically given as a decimal number (float), even if it is .0 (e.g. 10 / 2 would give 5.0).
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Casting a float (also known as real) number into an integer using int() will remove the decimal.
total = 100/10
print("The answer is" , total)
print("The answer is" , int(total))
The answer is 10.0
The answer is 10
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Data Types Task 1 (Time)
Write an input line with int to ask the current hour.
Write another input line with int to ask the current minute.
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Write a print line with str() that outputs this as a clock time.
Example solution:
What is the hour? 12
What is the minute? 44
The time is 12:44
Data Types Task 2 (Decimal)
Write an input line with int to ask for any number.
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Use float() in a print line to output number as a decimal.
Example solution:
Enter any number: 456
456.0