Do you know the method to โConvert String to Double in Python Language?โ If you are a newcomer to the Python Language Course, you should need to understand the concept. Otherwise, you are going to face a lot of troubles in the beginning itself.
The Python programming language is different than any other language. To make it small & concise, there are many different unique features involved. One of the features is the absence of Data Types which are required to declare any variable in the program.
In the absence of the Data types, Python uses String as the default data type. From that background, this article is developed. In this article, we will know why we need to convert Strings to Double or other data types multiple times in Python!
Summary or Key Highlights:ย
- Every input data in Python is stored as String data types by default.
- There is no Double Data Type concept present in Python language.
- If you want to store some precision values, the Float Data Type can be used.
- Performing any operation between different data types is not allowed in Python.
- To do such operations, conversion is needed in Python.
- There are three possible ways present to convert Strings to Python.
Why We Should Convert String To Double In Python?
In Python, when a programmer takes input using the built-in `input()` function, the input is captured as a string. This means that regardless of the value the user enters (whether it’s a number, text, or any other value), Python treats it as a sequence of characters, represented by a string.
As Python is a dynamically typed language it means data types of variables are not declared beforehand and Python will not know what the user will enter. Hence, it represents the input as a collection of characters.
Hereโs a simple example to illustrate the type of user input.
Code to illustrate the type of user input:
# Taking user input
message = input("Please enter a message: ")
pincode = input("Please enter the recipient pincode: ")
# Displaying the captured input
print("Message:", message , " " , type(message))
print("Pincode:", pincode, " ", type(pincode))
Output:
From the output, we can see despite varied data types, both user input of the message and pin code is
received as a string. So, now we can understand that the input-taking process in Python is different than any normal language.
Now, if any novice takes Number Input & directly performs an arithmetic operation on it, it will certainly prompt an error message. In the end, the programmer wants to do an Arithmetic Operation with a string value. We can understand the process with one example.
p = input("Enter Number: ") # Taking user input
p = p + 10 # Trying To Add
print("Result:", p) # Printing Values
Output :
The output shows that the TypeError message is coming as we are going to add the String Value with one integer value. This is the case for Double as well. If you want to add the string values with the Double the same TypeError message comes.
This is the reason, we have to convert String Values to Double in Python.
What Are The Methods To Convert String to Double in Python? Read Below
Now, it is time to jump to the core concept of the article. Here, we are going to write down the functions that can be used to Change the String Function to Double without having any kind of issues. You can pick up any function mentioned below to do so.
Here, at first, we are going to use the Float function as it is the most important & highly used inbuilt function. After Float(), we are going to introduce two different functions as well.
Using float() Function
ย The most straightforward method is to use the built-in float() function, which converts a string to a
floating-point number. It represents numbers in base-2 format. float() has a fixed number of bits allocated for the mantissa (fractional part) and the exponent in the binary representation.
# _pi is currently a String
_pi = "3.14159265359"
value = float(_pi)
print(" Type of Pi" , value , " ", type(value))
Steps of the Program:ย
- At first, a normal string value is declared in the program with the decimal values as string.
- Now, we will use the Syntax float(variable-name).
- It will promptly convert the string data & store value in one variable.
- If we print the variable, we will find the Type is changed.
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Output:
From the above output, we can see that the Class has now changed. It is now pointing to the Float variable. The Float Variable is the smaller part of the Double. So, we can say the string is now converted to a Double value.
Using Decimal Module
After the Float() Function, the Decimal function can be the next one. It is the function that works similarly to Float(). The Decimal Module provides precise decimal representation without rounding errors. It represents numbers in base-10 format.
from decimal import Decimal
value_str = "3.14159"
value = Decimal(value_str)
print(value, " " , type(value))
Steps of The Program:ย
- We have to first import the Decimal Function from the Decimal Library itself.
- Now, a string variable is stored in the program that will be used in the future.
- We will store the decimal value in the variable using the syntax decimal(variable-name).
- Now, we can print the Type to see that changes.
Output:
The above output clearly shows that the Class is now marked as the Decimal. As we are using the Decimal function, it is being changed to Decimal. In the previous one, it was the Float function as the Float is being used.
Using numpy Library:
NumPy library is mostly used when performing tasks on machine learning as it has more advanced
numerical functions. This can be another great alternative to change to Double from String in Python.
import numpy as np
golden_ratio = "1.61803398875"
phi = np.float64(golden_ratio)
print(phi, " ", type(phi))
Steps of the Program:ย
- We have to first call the Numpy in the program as NP to make it easy to use multiple times.
- Now, we will take a String Value with the decimal number in any variable.
- Using the syntax np.float64(Variable-Name), we will convert the value to the decimal.
- Now we will print the Type of the new variable.
Output:
From the above output, you can see that the Float64 is the new Type of the new variable. So, it is not the string number now. You can use the value for addition or any other arithmetic task. It will not provide any error.
What Are The Varied scenarios where you might need to convert a string to a double?
Now, before ending the topic, we are going to find out the scenarios where the Conversation from String to Double in Python Programming Language will become necessary. We will discuss the fields where such conversation is highly needed.
We are going to make a list of domains where we have to convert String Data Type to Double for any kind of reason. Let us see each scenario one by one.
Data Parsing:
If you read data from external sources like Databases, you are going to get the data in the String format. Now, if you want to work on it, you have to make it to the Double or any Number format. In such cases, this conversation method can be used.
Mathematical Computation:
While performing a large Mathematical Computation, the Conversation method is being used. If there are any string values present in the process, they should be converted before going into the Mathematical computation.
File I/O :
When parsing data from files, the data is often read as strings. If the file contains numeric values that you need to use for calculations, you would need to convert those strings to doubles before performing the calculations.
API Responses:
When working with APIs that provide data in string format, you might need to convert the string data to doubles to process it correctly.
Command-Line Arguments:
When a script or program accepts command-line arguments, these arguments are typically received as strings. If the arguments are supposed to be numeric values, you’d need to convert them to doubles.
Conclusion:
Converting strings to double (floating-point) values in Python is necessary when handling user inputs or working with numeric data. These techniques discussed differ based on specific use cases.
The primary method discussed involved a built-in `float()` function, which readily converts a string representation of a number to a floating-point value. However, for large floating numbers, it might give incorrect round-off values.
For situations very precision is important, the Decimal module comes in handy. Furthermore, NumPy offers more advanced features to work on floats and doubles. To clear the concept of float and double, you should first know the differences between them.
Key Takeaways:
- The String to Double conversation is the basic need of the Python programming language.
- As every input data is stored as a String in Python, to make it calculable, it should be in Double.
- The Float() Function is the best function to convert into Double.
- There are many different ways the Float() Function can be used.
- Along with the Float(), there are Decimal & Numpy Functions present.
- From Mathematical Calculation to Data Parsing, the String should be converted.
