How to Convert A String to an Integer In Python?

To convert a string to an integer in Python, you can use the int() function. Simply pass the string as an argument to the int() function, and it will return the corresponding integer value. However, make sure that the string contains only numerical characters, as trying to convert a string with non-numerical characters will result in a ValueError. Additionally, you can use the int() function with a base parameter to specify the base of the number system in the string (e.g., binary, hexadecimal). For example:

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str_num = "42"
int_num = int(str_num)
print(int_num)

This will output:

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42

How to convert a string to a signed integer in Python?

You can convert a string to a signed integer in Python using the int() function. By default, the int() function converts the given string to an integer, assuming it is a decimal number. If the string contains a positive value, it will be converted to a positive integer. To convert a string to a signed integer, you can specify the base parameter as 10.

Here's an example:

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# Convert a string to a signed integer
string_number = "-123"
signed_integer = int(string_number, 10)

print(signed_integer)

Output:

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-123

In this example, the string "-123" is converted to a signed integer using the int() function with the base parameter set to 10. The resulting signed integer is then printed out.

What is the behavior of int() function when converting a Unicode string to an integer in Python?

When converting a Unicode string to an integer in Python using the int() function, the function will raise a ValueError if the Unicode string contains any characters that are not valid digits. This is because the int() function expects a string representation of a valid base 10 number. In order to successfully convert a Unicode string to an integer, the string must only contain numeric characters.

For example:

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unicode_string = "123"
integer_value = int(unicode_string) # This will successfully convert the Unicode string "123" to an integer value of 123

invalid_unicode_string = "abc123"
integer_value = int(invalid_unicode_string) # This will raise a ValueError because the Unicode string "abc123" contains non-numeric characters

In summary, the int() function will only successfully convert a Unicode string to an integer if the string contains only valid numeric characters.

How to convert a hexadecimal string to an integer in Python?

You can convert a hexadecimal string to an integer in Python using the int() function with base 16. Here's an example:

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hex_string = "1A"
decimal_number = int(hex_string, 16)
print(decimal_number)

In this example, the hexadecimal string "1A" is converted to its decimal integer equivalent using the int() function with base 16. The output will be:

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26