Sololearn blogFloating numbers in Python
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Floating numbers in Python

Data has different types, it can be stored in. The main types are numbers, strings, list, tuples, set and dictionaries. In this article, we will focus on floating numbers, one of the form numbers that can be stored.

Floating numbers have numbers with a whole part and a fractional part separated by a decimal point(.) These numbers are not integers.

wholepart.fractionalpart

How to obtain floating numbers

By storing a number with a decimal point in a variable and printing it out.

float_number = 13.45
print(float_number)  # >> 13.45

We can also check the type the variable belongs to using the type notation “type()”.

float_number = 13.45
print(type(float_number))  # >> <class 'float'>

By dividing integers

maths_score = 12
science_score = 20
english_score = 30
mean_score = maths_score + science_score + english_score / 3
print(mean_score)  # >>  42.0
print(type(mean_score))  # >>  <class 'float'>

We can see in the code block above that the output is <42.0>, the whole part is 42 and the fractional part is 0.

By using the inbuilt float() method

float_num = float()
print(float_num)  # >> 0.0
print(type(float_num))  # >> <class 'float'>

Converting other data types to Float Using the inbuilt method float().

Data types like integers, strings and boolean can be converted to floats.

Example I – with integers

Integers are whole numbers, examples; 13, 40, 15, 60 

integer_number = 13to_float_num = float(integer_number)print("This is a floating number" , to_float_num) # >> 13.0

In the above code block, the result is “13.0”, <13> is the whole part, <0> is the fractional part, and it is separated by a decimal point<.>. Let’s check the types of the variables

integer_number = 13
to_float_num = float(integer_number)
print("Type for the variable - integer_number: ")
print(type(integer_number))
# >> Type for the variable - integer_number:
# >> <class 'int'>
print("Type for the variable - to_float_num: ")
print(type(to_float_num))
# >> Type for the variable - to_float_num:
# >> <class 'float'>

Example II – with strings

Strings that contain numbers (“40”, “40.345”)  and strings that contain some characters like: “infinity”, “inf”, “Nan” and “nan” are converted to floats apart from these examples of strings, the rest throw an error message.

  • Strings with numbers
string_num = "30"
to_float = float(string_num)
print(to_float)  # >> 30.0
print(type(to_float))  # <class 'float'>

string_num1 = "50.555555"
to_float1 = float(string_num1)
print(to_float1)  # >> 50.555555
print(type(to_float1))  # <class 'float'>
  • Strings with characters; “infinity”,”inf” and “nan”

When the characters “infinity” or “inf” no matter the case of the letters(lower or upper), the output is <inf>

string_text = "infinity"
string_text_alt = "inf"
to_float = float(string_text)
to_float_alt = float(string_text_alt)
print(to_float)  # >> inf
print(to_float_alt)  # >> inf
print(type(to_float))  # <class 'float'>
print(type(to_float_alt))  # <class 'float'>

When the characters “NAN” or “nan” no matter the case of the letters(lower or upper), the output is <nan>

string_text1 = "nan"
string_text_alt1 = "NAN"
to_float1 = float(string_text1)
to_float_alt1 = float(string_text_alt1)
print(to_float1)  # >> nan
print(to_float_alt1)  # >> nan
print(type(to_float1))  # <class 'float'>
print(type(to_float_alt1))  # <class 'float'>

Other strings with non-numeric characters  would not be converted to float

string_text = "Float number"
to_float = float(string_text)
print(to_float)  # >> could not convert string to float: 'Float number'

Example III – with booleans

Booleans have two statement: <True> or <False>. <True> when converted to float the output is <1.0> while <False> becomes <0.0>

bool_true = True
bool_false = False
to_float = float(bool_true)
to_float1 = float(bool_false)
print(to_float)  # >> 1.0
print(to_float1)  # >> 0.0
print(type(to_float))  # <class 'float'>
print(type(to_float1))  # <class 'float'>

Note: “True” is not the same as <True> the first is a string and it will throw and error, same as “False” and <False>

Example IV – from the input() method

This method is a substitute for numbers , infinity and nan in strings, any other from these strings will throw an error.

float_value = float(input("Enter a number or infinity or nan to convert to float: "))
print(float_value)  # >> 30.908
print(type(float_value))  # >> <class 'float'>

Arithmetic Operations

Floating numbers can perform all four main operations; addition, subtraction, multiplication and division.

  • Addition
float_num_1 = 20.34
float_num_2 = 2.0
add_float = float_num_1 + float_num_2
print(add_float)  # >> 22.34
  • Subtraction
float_num_1 = 20.34
float_num_2 = 2.0
sub_float = float_num_1 - float_num_2
print(sub_float)  # >> 18.34
  • Multiplication
float_num_1 = 20.34
float_num_2 = 2.0
multiply_float = float_num_1 * float_num_2
print(multiply_float)  # >> 40.68
  • Division
float_num_1 = 20.34
float_num_2 = 2.0
divide_float = float_num_1 / float_num_2
print(divide_float)  # >> 10.17

Conclusion

Floating numbers are an integral part of real-world computation. In finance for money, in engineering for precision control, and in various fields for different purposes. Therefore, It is important to understand how they work and how they can be used. To know more about floats in the python programming language, check here.

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