In this post, we'll explore the different methods Python provides to read files, along with best practices and code examples.
READ A FILE IN PYTHON
Getting Started
Working with files is a fundamental skill in Python programming. Whether you're analyzing data, reading configuration files, or processing text, understanding how to read files in Python efficiently and correctly is essential.
Opening a File in Python
To read a file, you first need to open it using Python’s built-in open() function.
file = open('filename.txt', 'mode') file = open('myfile.txt', 'r')'r'– Read (default)'rb'– Read in binary mode'r+'– Read and write
Read File in Python
In Pythong, reading a file is easy as other language. The Python read() function is used to read the entire content of a file as a string. The contents can be text data, numbers, or binary data. The following code examples read a text file in python. The following codes read a text file in python.
with open('filename.txt', 'r') as file:
content = file.read()
print(content)
# Program to show read a text file in python
_fileobject=open("D:\aricle.txt",'r')#load file into python
str=_fileobject.read();#python read text file
print("\nThe contents of aricle.txt are :\n",str)#python printing to file
_fileobject.Close() # python close file
In the above example file aricle.txt is read using the read() functions. Python read() function returns the read contents and stores them in str, which can be printed later. Note that read() function can be used in the case when the file size is small .
Read a Line
with open('aricle.txt', 'r') as file:
line = file.readline()
while line:
print(line.strip()) # strip() removes the newline
line = file.readline()
Reads all lines into a list
with open('aricle.txt', 'r') as file:
line = file.readline()
while line:
print(line.strip()) # strip() removes the newline
line = file.readline()
for line in lines:
print(line.strip())
Get Positions
The python tell() function is used to determine the current position within the file, in other words, the next read will occur at that may byte from the beginning of the file.
# Program to show read a text file in python
_fileobject=open("D:\aricle.txt",'r')#load file into python
str=_fileobject.read();#python read text file
p=_fileobject.tell(); # python tell function
print("\nCurrent position of file :\n",p)#python printing to file
_fileobject.Close() #python close function
tell method in python
Change Positions
The python seek() function to change the current position in a file. This function required two parameters that are offset and the form. The offset parameter indicates the number of bytes to be moved and the form parameter specifies the reference position from where the bytes are to be moved.
# Program to show read a text file in python
_fileobject=open("D:\aricle.txt",'r')#load file into python
str=_fileobject.read();#python read text file
p=_fileobject.tell(); # python tell function
print("\nCurrent position of file :\n",p)#python printing to file
_fileobject.seek(0,0)#seek function in python
_fileobject.Close() #python close function
Python File Seek
In the above example form value is 0, which means use the beginning of the file as the reference position. The python seek() function takes three value as form parameter(0,1,2). 1 is for use the current position as the reference position and 2 indicates the position of the file would be taken as the reference position.
Handling File Errors
try:
with open('example.txt', 'r') as file:
print(file.read())
except FileNotFoundError:
print("The file was not found.")
except IOError:
print("An I/O error occurred.")
Note:-In Pythong, reading a file using the with statement is a best practice, it automatically manage resources. Hence always use the with statement while reading files.
Summary
Python offers a clean and flexible approach to reading files. Whether you're reading the entire file at once or processing it line by line, using the appropriate method can help you write efficient and readable code. I hope this was helpful to you.
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