# Python: Truncate a Float (6 Different Ways) In this tutorial, you’ll learn how to use Python to truncate a float, to either no decimal places or a certain number of decimal places. You’ll learn how to do this using the built-in `int()` function, the `math` library, and string methods, including Python f-strings. You’ll also learn how to truncate a list of floats.

Being able to truncate values in Python has a number of important benefits, such as being able to output numbers in a more presentation-ready format. Being able to output values in a more reader friendly format is an important skill to learn in order to make your data easier to look at.

## Use the int Function to Truncate a Float in Python

The built-in `int()` function takes a float and converts it to an integer, thereby truncating a float value by removing its decimal places.

The `int()` function works differently than the `round()` and `floor()` function (which you can learn more about here). The function only removes anything following the decimal, regardless of what follows it. This is differently than the `round()` function, as it does not round up. It’s also different from the `floor()`, which returns an integer now greater than a number.

Let’s see how we can use the `int()` function to truncate a float in Python:

```# Truncate a float in Python with int()

float1 = 123.356
float2 = -2434.545

print(int(float1))
print(int(float2))

# Returns:
# 123
# -2434```

We can see here that anything following the decimal place is truncated.

In the next section, you’ll learn how to use the `math` library to truncate a float in Python.

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## Use the Math Library to Truncate a Float in Python

Similar to the `int()` function, the `math` library has a library that can be helpful to truncate a float in Python, the `trunc()` function.

While it may seem trivial to use another library to do this, it can help your code read a little clearer to explain what the function is doing and why it’s doing it.

Because our intention is to truncate a float, the `trunc()` function makes this explicitly clear, whereas the `int()` function doesn’t.

Let’s see how we can use the `trunc()` function to truncate some numbers in Python:

```# Truncate a float in Python with math.trun()
import math

float1 = 123.356
float2 = -2434.545

print(math.trunc(float1))
print(math.trunc(float2))

# Returns:
# 123
# -2434```

We can see here that the same result is returned as when using the `int()` function.

In the next section, you’ll learn how to use string methods to truncate a float in Python.

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## Use String Methods to Truncate a Float in Python

We can also use string methods to truncate a float in Python. This works by first converting a float to string and then manipulating the string.

Using the `str.split()` method, we can split a string at a period and keep only the first section of the split. You can learn more about splitting strings in this tutorial.

Let’s see how we can truncate a float in Python by using the `str.split()` method.

```# Truncate a float in Python with str.split()
float1 = 123.356
float2 = -2434.545

print(str(float1).split('.'))
print(str(float2).split('.'))

# Returns:
# 123
# -2434```

Let’s see how this works:

1. We first convert the float to a string
2. We then split the string using the `.` character
3. Finally, we return the first item returned (the piece preceding the decimal)

In the next section, you’ll learn how to use f-strings to truncate a float in Python.

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## Use f-strings to Truncate a Float in Python

There may be times that you want to truncate a float to a certain number of decimal points. This can be helpful, say, when displaying currencies or percentages.

For this, we can easily use string formatting by way of the helpful f-string features in Python. With this, we can specify the number of decimal points to keep and convert the string back to a float.

```# Truncate a float in Python with f-strings
float1 = 123.356
float2 = -2434.545

# Keep two decimal places
print(float(f'{float1:.2f}'))
print(float(f'{float2:.2f}'))

# Returns:
# 123.36
# -2434.55```

We can see here that we first convert the float to a string, returning only a certain number of decimal places. We then convert the string back to a float, using the `float()` function.

Want to learn more about Python f-strings? Check out my in-depth tutorial, which includes a step-by-step video to master Python f-strings!

## Truncate a List of Floats in Python Using a For Loop

There may be times when you are given a list of floats and need truncate all of them. One of the ways in which you can do this is by using a Python for loop.

When doing this, we can loop over each item in the list, truncate it, and add it to a new list.

Let’s see what this looks like in Python:

```# Truncate a list of floats using a for loop
floats = [1.234, 45.543, 132.87, 76.989]
truncated = list()

for float in floats:
truncated.append(int(float))

print(truncated)

# Returns: [1, 45, 132, 76]```

What we’ve done here is:

1. Instantiated a new, empty list to hold our truncate values
2. Looped over each item in our list of floats and truncated it using the `int()` function
3. Appended the truncated item to our list

We can also use a list comprehension to make this process a little bit easier, saving us the step of instantiating a new list first.

## Truncate a List of Floats in Python Using a List Comprehension

The above section showed how to use a Python for loop to truncate a list of floats. We can also use a Python list comprehension to do this, thereby saving us some visual clutter and the need to instantiate an empty list first.

Let’s see how we can use a list comprehension to accomplish this:

```# Truncate a list of floats using a list comprehension
floats = [1.234, 45.543, 132.87, 76.989]
truncated = [int(item) for item in floats]

print(truncated)

# Returns: [1, 45, 132, 76]```

To learn more about Python list comprehensions, check out the image below that shows how they work:

Want to learn more about Python list comprehensions? Check out this in-depth tutorial that covers off everything you need to know, with hands-on examples. More of a visual learner, check out my YouTube tutorial here.

## Conclusion

In this tutorial, you learned how to use Python to truncate a float. You learned how to do this using the `int()` function, the `math` library, and string methods. You also learned how to use for loops and list comprehensions to truncate a list of floating point values in Python.

To learn more about the `math.trunc()` function, check out the official documentation here.