Python’s built-in

function takes one integer argument and returns a hexadecimal string with prefix **hex(integer)**`"0x"`

. If you call `hex(x)`

on a non-integer `x`

, it must define the `__index__()`

method that returns an integer associated to `x`

. Otherwise, it’ll throw a `TypeError: object cannot be interpreted as an integer`

.

Argument | `integer` | An integer value or object implementing the `__index__()` method. |

Return Value | `string` | Returns a string of octal numbers, prefixed with `"0x"` . |

Input:`hex(1)`

Output:`'0x1'`

Input:

`hex`

(2)Output:`'0x2'`

Input:

`hex`

(4)Output:`'0x4'`

Input:

`hex`

(8)Output:`'0x8'`

Input:

`hex`

(10)Output:`'0xa'`

Input:`hex(11)`

Output:`'0xb'`

Input:`hex(256)`

Output:`'0x100'`

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## Python hex() for Custom Objects

If you call `hex(x)`

on a non-integer or custom object `x`

, it must define the `__index__()`

method that returns an integer associated to `x`

.

class Foo: def __index__(self): return 10 f1 = Foo() print(hex(f1)) # '0xa'

## How to Fix “TypeError: ‘float’ object cannot be interpreted as an integer”?

Python’s `hex()`

function can only convert whole numbers from any numeral system (e.g., decimal, binary, octary) to the hexadecimal system. It cannot convert floats to hexadecimal numbers. So, if you pass a float into the `hex()`

function, it’ll throw a `TypeError: 'float' object cannot be interpreted as an integer`

.

>>> hex(11.14) Traceback (most recent call last): File "<pyshell#20>", line 1, in <module> hex(11.14) TypeError: 'float' object cannot be interpreted as an integer

To resolve this error, you can round the float to an integer using the built-in `round()`

function or you write your own custom conversion function:

## How to Convert a Float to a Hexadecimal Number in Python?

To convert a given float value to a hex value, use the `float.hex()`

function that returns a representation of a floating-point number as a hexadecimal string including a leading `0x`

and a trailing `p`

and the exponent.

Note that the exponent is given as the power of 2 by which it is scaled—for example, `0x1.11p+3`

would be scaled as `1.11 * 2^3`

using the exponent 3.

>>> 3.14.hex() '0x1.91eb851eb851fp+1' >>> 3.15.hex() '0x1.9333333333333p+1'

Alternatively, if you need a non-floating point hexadecimal representation similar to most online converters, use the command `hex(struct.unpack('<I', struct.pack('<f', f))[0])`

.

import struct def float_to_hex(f): return hex(struct.unpack('<I', struct.pack('<f', f))[0]) print(float_to_hex(3.14)) print(float_to_hex(88.88))

The output are the octal representations of the float input values:

0x4048f5c3 0x42b1c28f

**Sources**:

- https://docs.python.org/3/library/stdtypes.html#float.hex
- https://gregstoll.com/~gregstoll/floattohex/
- https://www.scadacore.com/tools/programming-calculators/online-hex-converter/
- https://stackoverflow.com/questions/23624212/how-to-convert-a-float-into-hex

## Hex Formatting Subproblems

Let’s consider some formatting variants of the hexadecimal conversion problem converting a number into ** lowercase/uppercase** and

**. We use the Format Specification Language. You can learn more on this topic in our detailed blog tutorial.**

*with/without prefix*We use three semantically identical variants for each conversion problem.

### How to Convert a Number to a Lowercase Hexadecimal With Prefix

>>> '%#x' % 12 '0xc' >>> f'{12:#x}' '0xc' >>> format(12, '#x') '0xc'

### How to Convert a Number to a Lowercase Hexadecimal Without Prefix

>>> '%x' % 12 'c' >>> f'{12:x}' 'c' >>> format(12, 'x') 'c'

### How to Convert a Number to an Uppercase Hexadecimal With Prefix

>>> '%#X' % 12 '0XC' >>> f'{12:#X}' '0XC' >>> format(12, '#X') '0XC'

### How to Convert a Number to an Uppercase Hexadecimal Without Prefix

>>> '%X' % 12 'C' >>> f'{12:X}' 'C' >>> format(12, 'X') 'C'

👉 **Recommended Tutorial**: Convert Hex String to Hex Number in Python

## Summary

Python’s built-in

function takes one integer argument and returns a hexadecimal string with prefix **hex(integer)**`"0x"`

.

>>> hex(1) '0x1' >>> hex(2) '0x2' >>> hex(4) '0x4' >>> hex(8) '0x8' >>> hex(10) '0xa' >>> hex(11) '0xb' >>> hex(256) '0x100'

🧑💻 **Recommended**: Python Integer to Hex [Ultimate Guide]

If you call `hex(x)`

on a non-integer `x`

, it must define the `__index__()`

method that returns an integer associated to `x`

.

class Foo: def __index__(self): return 10 f1 = Foo() print(hex(f1)) # '0xa'

Otherwise, it’ll throw a `TypeError: object cannot be interpreted as an integer`

.

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