Python Float to Int Conversion

Safest way to convert float to integer in python?

All integers that can be represented by floating point numbers have an exact representation. So you can safely use int on the result. Inexact representations occur only if you are trying to represent a rational number with a denominator that is not a power of two.

That this works is not trivial at all! It's a property of the IEEE floating point representation that int∘floor = ⌊⋅⌋ if the magnitude of the numbers in question is small enough, but different representations are possible where int(floor(2.3)) might be 1.

To quote from Wikipedia,

Any integer with absolute value less than or equal to 2²⁴ can be exactly represented in the single precision format, and any integer with absolute value less than or equal to 2⁵³ can be exactly represented in the double precision format.

How do I parse a string to a float or int?

>>> a = "545.2222"
>>> float(a)
545.22220000000004
>>> int(float(a))
545

Python float to Decimal conversion

Python <2.7

"%.15g" % f

Or in Python 3.0:

format(f, ".15g")

Python 2.7+, 3.2+

Just pass the float to Decimal constructor directly, like this:

from decimal import Decimal
Decimal(f)

Value error converting from float to int in python (very weird problem)

https://docs.python.org/3/library/functions.html#int

If x is not a number or if base is given, then x must be a string, bytes, or bytearray instance representing an integer literal in radix base. Optionally, the literal can be preceded by + or - (with no space in between) and surrounded by whitespace. A base-n literal consists of the digits 0 to n-1, with a to z (or A to Z) having values 10 to 35. The default base is 10. The allowed values are 0 and 2–36. Base-2, -8, and -16 literals can be optionally prefixed with 0b/0B, 0o/0O, or 0x/0X, as with integer literals in code. Base 0 means to interpret exactly as a code literal, so that the actual base is 2, 8, 10, or 16, and so that int('010', 0) is not legal, while int('010') is, as well as int('010', 8).

It is rejecting the decimal point in your input string when you pass it to the builtin int function.

num = "1.5"
print(type(num)) # <class 'str'>
print(int(num)) # ValueError: invalid literal for int() with base 10: '1.5'

num = "2"
print(type(num)) # <class 'str'>
print(int(num)) #2

num = 1.5
print(type(num)) # <class 'float'>
int_num = int(num)
print(type(int_num)) # <class 'int'>
print(int_num) # 1

num = "1.5"
float_num = float(num)
print(type(float_num)) # <class 'float'>
print(float_num) # 1.5
int_num = int(float_num)
print(type(int_num)) # <class 'int'>
print(int_num) # 1

Convert floats to ints in Pandas?

To modify the float output do this:

df= pd.DataFrame(range(5), columns=['a'])
df.a = df.a.astype(float)
df

Out[33]:

          a
0 0.0000000
1 1.0000000
2 2.0000000
3 3.0000000
4 4.0000000

pd.options.display.float_format = '{:,.0f}'.format
df

Out[35]:

   a
0  0
1  1
2  2
3  3
4  4

How to convert int to float in python?

Other than John's answer, you could also make one of the variable float, and the result will yield float.

>>> 144 / 314.0
0.4585987261146497

Python: Convert Float to Int in List

Please try to provide full error traceback documentation in future posts to help people better assist you.

It's fundamentally impossible to concatenate type int to a str initialization unless you cast the int as a str (i.e., the opposite of what you're trying to do). I'm not really sure what your end goal is here, but I can assure you that the problem is not that the strings which you are trying to cast as integers are not being converted (in the case where they are numbers in string form), it's rather just that you can't concatenate them to an empty string.

If there's something else you're trying to do here, I can try to help if you can elaborate.

Convert float to integer to get number without dot and zero

If you are dealing with numpy array you can do the following

y = np.array(np.round(x), dtype=int)

However if its just a number int(round(x)) will do the job.