In Python, every object (including variables) has a unique identifier, which is essentially its address in memory. You can use the built-in function id() to retrieve this identifier. To get the actual memory address, you can then format it in hexadecimal.
Here's a simple program that demonstrates this:
def print_address(var):
address = id(var)
print(f"Address of variable is: 0x{address:x}")
# Example usage:
x = 42
print_address(x)
When you run the above program, it will print the memory address of the variable x.
However, note that the concept of "address" is a bit abstracted in higher-level languages like Python when compared to languages like C or C++. The id() function provides a unique identifier for the object during its lifetime, but you shouldn't rely on or use this address for low-level memory operations in Python as you might in other languages.
If you want to make a Perl or Python script print each line of the program as it is executed, you can achieve this by adding some code that reads and prints the lines of the script file itself. Here's how to do it in both Perl and Python:
You can use the __DATA__ filehandle in Perl to read the source code of the script itself. Here's an example:
#!/usr/bin/perl
use strict;
use warnings;
# Open the script file for reading
open my $script_file, '<', $0 or die "Cannot open script: $!";
# Read and print each line of the script
while (my $line = <$script_file>) {
print $line;
# Add your code here to execute the line, if needed
}
# Close the script file
close $script_file;
# Rest of your Perl script goes here
In this Perl script:
We open the script file (identified by $0, which is the name of the currently running script) for reading.
We read and print each line of the script. You can also add code to execute each line if that's your goal.
We close the script file when we're done.
You can use the __file__ attribute to get the path to the currently running Python script and then open and read it line by line. Here's an example:
#!/usr/bin/python
# Open the script file for reading
with open(__file__, 'r') as script_file:
for line in script_file:
print(line)
# Add your code here to execute the line, if needed
# Rest of your Python script goes here
In this Python script:
We use __file__ to get the path to the currently running script.
We open the script file for reading and read it line by line, printing each line.
You can add code to execute each line as needed.
Note that this approach will print the entire script, including comments and blank lines. If you want to print only the lines that contain executable code, you may need to add some logic to skip comments and empty lines.
To find and print multiple matches using regular expressions in Python, you can use the re module. Here's a basic example of how to do this:
import re # Sample text containing email addresses text = "My email addresses are [email protected] and [email protected]." # Define a regular expression pattern to match email addresses pattern = r'\S+@\S+' # Use the findall function to find all matches in the text matches = re.findall(pattern, text) # Print the found matches for match in matches: print(match)
In this example:
We import the re module, which provides regular expression support in Python.
We define a sample text string (text) that contains email addresses.
We define a regular expression pattern (pattern) to match email addresses. The pattern \S+@\S+ matches sequences of non-whitespace characters (\S+) followed by an @ symbol and more sequences of non-whitespace characters.
We use the re.findall() function to find all matches of the pattern in the text. This function returns a list of all matches found in the input string.
We iterate through the list of matches and print each match.
When you run this code, it will find and print all email addresses in the text variable. You can modify the pattern variable to match different patterns as needed.