float() in Python
Python float() function is used to return a floating-point number from a number or a string.
Syntax: float(x)
float() Parameters
The method only accepts one parameter and that is also optional to use. Let us look at the various types of argument, the method accepts:
A number: Can be an integer or a floating-point number.
A String :
- Must contain numbers of any type.
- Any left or right whitespaces or a new line is ignored by the method.
- Mathematical Operators can be used.
- Can contain NaN, Infinity or inf (any cases)
Values that the float() method can return depending upon the argument passed
- If an argument is passed, then the equivalent floating-point number is returned.
- If no argument is passed then the method returns 0.0.
- If any string is passed that is not a decimal point number or does not match any cases mentioned above then an error will be raised.
- If a number is passed outside the range of Python float then OverflowError is generated.
float in Python example
Example 1: How float() works in Python
Python3
# Python program to illustrate# Various examples and working of float()# for integersprint(float(21.89))# for floating point numbersprint(float(8))# for integer type stringsprint(float("23"))# for floating type stringsprint(float("-16.54"))# for string floats with whitespacesprint(float(" -24.45 \n"))# for inf/infinityprint(float("InF"))print(float("InFiNiTy"))# for NaNprint(float("nan"))print(float("NaN"))# Error is generated at lastprint(float("Geeks")) |
Output:
21.89 8.0 23.0 -16.54 -24.45 inf inf nan nan
All lines are executed properly but the last one will return an error:
Traceback (most recent call last):
File "/home/21499f1e9ca207f0052f13d64cb6be31.py", line 25, in
print(float("Geeks"))
ValueError: could not convert string to float: 'Geeks'Example 2: float() for infinity and Nan
Python3
# Python program to illustrate# Various examples and working of float()# for inf/infinityprint(float("InF"))print(float("InFiNiTy"))# for NaNprint(float("nan"))print(float("NaN")) |
Output:
inf inf nan nan
Example 3: Converting an Integer to a Float in Python
Python3
# python code to convert int# floatnumber = 90result = float(number)print(result) |
Output:
90.0
Example 4: Converting a String to a Float in Python
Python3
# python code to convert string# to floatstring = "90"result = float(string)print(result) |
Output:
90.0
Example 5: Python float() exception
Python3
number = "geeks"try: print(float(number))except ValueError as e: print(e) |
Output:
could not convert string to float: 'geeks'
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