How To Convert A List Of Strings To Integers In Python?

If you’re looking to convert a list of strings to integers in Python, there are a few ways you can do it. In this article, we’ll show you how to convert a list of strings to integers in Python using the built-in int() function and a few other methods.

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Introduction

In Python, there are a number of ways to convert a list of strings to a list of integers. One way is to use the built-in function map(). Another way is to use a for loop.

The map() function takes a function and an iterable as arguments. It applies the function to each element of the iterable and returns a list of the results. In this case, we want to use the int() function, which takes a string and converts it to an integer.

Here’s an example:

“`python
strings = [‘1’, ‘2’, ‘3’, ‘4’, ‘5’]

# Use `map` to apply `int` to each element in `strings`
integers = list(map(int, strings))

# Print the integers
print(integers)

# [1, 2, 3, 4, 5]

“`

What is the need to convert strings to integers in Python?

One of the most common need for data wrangling with Python is to convert data from one type to another. In this article, we will go over converting data from strings to integers in Python.

Converting strings to integers in Python is quite simple. All you need to do is use the built-in int() function. The int() function takes in a string and returns an integer.

Here is an example:

“`python
>>>int(“1”)
1
>>>int(“2”)
2
>>>int(“3”)
3

“`

How to convert a list of strings to integers in Python?

Python makes it easy to work with lists of strings. But sometimes, you will need to convert a list of strings into a list of integers.

There are many ways to do this, but the easiest way is to use the built-in int() function.

Here is an example:

my_list = [‘1′,’2′,’3′,’4’]
my_list = [int(i) for i in my_list]
print(my_list)
#OUTPUT: [1, 2, 3, 4]

Different methods to convert strings to integers in Python

There are a few methods to convert strings to integers in Python. The most common method is using the built-in int() method. This converts the string representation of a number to an actual number. However, there are other ways as well which we will discuss in this article.

First, let’s take a look at the int() method. We can use this to convert strings to integers easily:

“`
>>> int(“10”)
10
>>> int(“-10”)
-10
“`

The int() method

The int() method takes two parameters: the value to convert and the base in which to express that value. For example, to convert the string “11” to the integer 11 in base 10, you would pass “11” as the first parameter and 10 as the second parameter. The second parameter is optional, and if you omit it, Python will assume that you want to convert the value in base 10.

The int() method can be used to convert floating-point values to integers, but it will round off the fractional part of the number:

>>> int(3.14)
3

The map() function

The map() function in Python takes in a function and a list as argument. The function is called with a lambda function, which converts the string to an int.

my_list = [‘1’, ‘2’, ‘3’]
result = map(lambda x: int(x), my_list)

# Output: [1, 2, 3]

The list comprehension method

Python provides a magical join() method that takes a character and joins all the elements of the list together, separated by that character.

But what if you want to convert a list of strings to integers?

There are a few methods you can use. The most straightforward is to use the built-in int() function:

int_list = [int(i) for i in str_list]
But this has some pitfalls. For example, it fails when you have non-numeric strings in your list:

int(’10’) # works fine
int(‘ten’) # ValueError: invalid literal for int() with base 10: ‘ten’
If you’re not sure if all the strings in your list can be converted to integers, you can use the try/except approach:

int_list = []
for i in str_list:
try: # attempt conversion to int dfsafasdfadsfadsfadsfadsfdasfdafsdfdafsdfsafadsfdafdsfdsfadfrdsdsytfyuwerq879245r970240980312849023849028340982034902384092384ut23984230948203yuiop[p=-0=-098765tyuio[o-0=-098767tgbnhgttretgbnhyjkmkONMBVGCXSAEDFGHJKLZXCVBNM,./;'[]\=-098766543210ZXCVBNMQWERTYUIOPASDFGHJKLNM<>?:”{}|`1234567890-=qwertyuiop[]\asdfghjkl;’zxcvbnm,./QWERTYUIOP{}|ASDFGHJKL:”ZXCVBNM<>? [email protected]#$%^&*()_+olqqwertfrtyuioiuytrertzselectthecount(*)frominformation_schema.tableswheretable_type=’base table’groupbytable_schemaorderby2 desc; limit0,1informationschematablesandcolumnsprocedureinformationaldependenceliveupdatedetectioneddg”

The reduce() function

The reduce() function is used to apply a function to a list of elements in order to reduce the list to a single value. The reduce() function takes two arguments:

-The function to be applied
-The list to which the function is to be applied
The function passed to reduce() must take two arguments and return a single value. The first argument is the accumulated value and the second argument is the current value from the list.

The filter() function

The filter() function in Python takes in a function and a list as arguments. The function is called with all the items in the list and a new list is returned which contains items for which the function returns True.

In this case, we want to convert all the strings in the list to integers. So, we would need a function which takes in a string and converts it to an integer and returns True. We can do that using the int() method in Python.

The following code would achieve our desired result:
“`
new_list = list(filter(lambda x: int(x), old_list))
“`

Conclusion

Summing up, in this article we have seen how to convert a list of strings to integers in Python. We have discussed both mutable and immutable methods for doing so. We have also looked at some Python built-in functions that can help us with this task.

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