Python Code For Obtaining The Mean Value From A Text File

In Python programming, extracting data from files is a common task. One such task is to calculate the mean value of numerical data stored in a text file. This article will guide you through the process of writing a Python program to read data from a text file and compute the mean value.

Python Program to Calculate Mean Value from a Text File

Below are some of the ways by which we can calculate the mean value from a text file in Python:

• Using Basic Python Iteration
• Using Basic File Handling and List Comprehension
• Using the statistics Module
• Using NumPy

data.txt

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Calculate Mean Value from a Text File Using Basic Python Iteration

In this example, a file named “data.txt” is opened and read line by line. Each line, interpreted as an integer, is added to a running total, and the count of lines is incremented. Finally, the mean value is calculated by dividing the total by the count, and the result is printed as the mean value.

Python3

# Open the file
with open("data.txt", "r") as file:
    # Initialize variables
    total = 0
    count = 0

    # Iterate through each line
    for line in file:
        # Convert line to integer and add to total
        total += int(line)
        count += 1

# Calculate the mean
mean = total / count

# Output the mean value
print("Mean:", mean)

Output:

Mean: 30.0

Calculate Mean Value from a Text File Using List Comprehension

In this example, the file “data.txt” is opened, and its contents are read into a list called lines using readlines(). Subsequently, the lines are converted to integers, stripping any leading or trailing whitespace, and stored in the data list. The mean of the data is then calculated by dividing the sum of the values by the length of the list, and the result is printed as the mean value.

Python3

# Open the file
with open("data.txt", "r") as file:
    # Read lines from the file
    lines = file.readlines()

# Convert lines to integers and calculate the mean
data = [int(line.strip()) for line in lines]
mean = sum(data) / len(data)

# Output the mean value
print("Mean:", mean)

Output:

Mean: 30.0

Calculate Mean Value from a Text File Using statistics Module

In this example, the file “data.txt” is opened and its contents are read line by line, converting each line to an integer and storing them in the data list using a list comprehension. The mean of the data is then calculated using the statistics.mean function from the Statistics module, and the result is printed as the mean value.

Python3

import statistics

# Read data from the text file
with open("data.txt", "r") as file:
    data = [int(line.strip()) for line in file]

# Calculate the mean using statistics module
mean = statistics.mean(data)

# Output the mean value
print("Mean:", mean)

Output:

Mean: 30.0

Calculate Mean Value from a Text File Using NumPy

In this example, the NumPy library is used to efficiently read numerical data from the “data.txt” file. The np.loadtxt function is employed for this purpose. Subsequently, the mean value of the data is computed using np.mean, and the result is printed as the mean value.

Python3

import numpy as np

# Read data from the text file
data = np.loadtxt("data.txt")

# Calculate the mean
mean_value = np.mean(data)

# Output the mean value
print("Mean:", mean_value)

Output:

Mean: 30.0

Conclusion

In this article, we’ve discussed how to write a Python program to obtain the mean value from a text file. By utilizing file handling techniques and basic arithmetic operations, we can efficiently extract and analyze data stored in text files. This approach is applicable to various scenarios where data analysis or processing from files is required in Python programming.