72 lines
2.0 KiB
Markdown
72 lines
2.0 KiB
Markdown
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---
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title: How to Convert Strings into Integers in Python
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---
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## How to Convert Strings into Integers in Python
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Just like the `str()` built-in, Python also offers a handy built-in which takes a string object as an argument and returns the corresponding integer object.
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#### Example Usage:
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```py
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# Here age is a string object
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age = "18"
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print(age)
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# Converting string to integer
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int_age = int(age)
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print(int_age)
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```
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Output
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```py
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18
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18
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```
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Here although the output is visually similar but you should keep in mind that the first line prints a string object while the line next to it prints a integer object which is further illustrated in the next example:
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```py
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age = "18"
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print(age+2)
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```
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Output:
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```py
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Traceback (most recent call last):
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File "<stdin>", line 1, in <module>
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TypeError: cannot concatenate 'str' and 'int' objects
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````
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The error should make it clear to you that you need to convert the `age` object to an integer before adding something to it.
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```py
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age = "18"
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age_int = int(age)
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print(age_int+2)
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```
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Output:
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```py
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20
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```
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But you should keep in mind some special cases:
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1. A floating point(an integer with fractional part) as an argument will return the float rounded down to the nearest whole integer.
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For example : `print(int(7.9))` will print `7`.
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Also `print(int("7.9"))` will result an error since the string is an invalid argument to convert to an integer.
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```py
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Traceback (most recent call last):
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File "<stdin>", line 1, in <module>
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ValueError: invalid literal for int() with base 10: '7.9'
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```
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2. Also any integer in words if given as an argument will return the same error as above:
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`print(int("one"))` will give an error as follows:
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```py
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Traceback (most recent call last):
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File "<stdin>", line 1, in <module>
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ValueError: invalid literal for int() with base 10: 'one'
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```
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#### More Information:
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Official documentation for `int()` built-in can be found <a href='https://docs.python.org/3.6/library/functions.html#int' target='_blank' rel='nofollow'>here</a>
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