- PYTHON FIND WORD IN FILE WITH RE HOW TO
- PYTHON FIND WORD IN FILE WITH RE FULL
- PYTHON FIND WORD IN FILE WITH RE SOFTWARE
- PYTHON FIND WORD IN FILE WITH RE CODE
You pass chunk to isPhoneNumber() to see whether it matches the phone number pattern ❷, and if so, you print the chunk.Ĭontinue to loop through message, and eventually the 12 characters in chunk will be a phone number. On the next iteration, i is 1, and chunk is assigned message (the string 'all me at 41'). For example, on the first iteration, i is 0, and chunk is assigned message (that is, the string 'Call me at 4').
On each iteration of the for loop, a new chunk of 12 characters from message is assigned to the variable chunk ❶. When this program is run, the output will look like this: Replace the last four print() function calls in isPhoneNumber.py with the following:
PYTHON FIND WORD IN FILE WITH RE CODE
You would have to add even more code to find this pattern of text in a larger string. Calling isPhoneNumber() with 'Moshi moshi' will return False the first test fails because 'Moshi moshi' is not 12 characters long. If the program execution manages to get past all the checks, it returns True ❼.Ĭalling isPhoneNumber() with the argument '41' will return True. The rest of the function checks that the string follows the pattern of a phone number: The number must have the first hyphen after the area code ❸, three more numeric characters ❹, then another hyphen ❺, and finally four more numbers ❻.
Then it checks that the area code (that is, the first three characters in text) consists of only numeric characters ❷.
First the code checks that the string is exactly 12 characters ❶. If any of these checks fail, the function returns False. The isPhoneNumber() function has code that does several checks to see whether the string in text is a valid phone number. When this program is run, the output looks like this: Open a new file editor window and enter the following code then save the file as isPhoneNumber.py: Let’s use a function named isPhoneNumber() to check whether a string matches this pattern, returning either True or False. You know the pattern: three numbers, a hyphen, three numbers, a hyphen, and four numbers. Say you want to find a phone number in a string. In fact, tech writer Cory Doctorow argues that even before teaching programming, we should be teaching regular expressions:įinding Patterns of Text Without Regular Expressions
PYTHON FIND WORD IN FILE WITH RE SOFTWARE
Regular expressions are huge time-savers, not just for software users but also for programmers. Regular expressions are helpful, but not many non-programmers know about them even though most modern text editors and word processors, such as Microsoft Word or OpenOffice, have find and find-and-replace features that can search based on regular expressions. This is how you, as a human, know a phone number when you see it: 41 is a phone number, but 4,155,551,234 is not. You may not know a business’s exact phone number, but if you live in the United States or Canada, you know it will be three digits, followed by a hyphen, and then four more digits (and optionally, a three-digit area code at the start). Regular expressions go one step further: They allow you to specify a pattern of text to search for. You may be familiar with searching for text by pressing CTRL-F and typing in the words you’re looking for. Lesson 23 - Regular Expressions Introduction Users/darren/Desktop/test/test 1 level/test 2 level/article 3.Pattern Matching with Regular Expressions Users/darren/Desktop/test/test 1 level/article 2.rtf If I run this I get the following output: /Users/darren/Desktop/test/article 1.rtf
PYTHON FIND WORD IN FILE WITH RE FULL
If you want to print out the full path for the file you can replace print(file) with: print(os.path.join(path, file)) In my case, it prints the following: article 1.rtf We will then check to see if that file's name starts with art and if it does we will print out the file name. In each directory we loop through each file. os.walk will allow us to go through all the subdirectories as well. The code is very similar, but now we use os.walk instead of os.listdir. for path, currentDirectory, files in os.walk("/Users/darren/Desktop/test"): In this section we will look at how we can do this recursively, meaning, listing all files in the given directory and all of its subdirectories where the file starts with a given string/prefix. In the first section we looked at how we can list all files in a given directory with a given string/prefix. In my case, the following prints out: article 1.rtf Find files recursively On each iteration it will check to see if the filename starts with art, if it does, it will print it out. The above code will loop through all the files in my test directory. To loop through the provided directory, and not subdirectories we can use the following code: for file in os.listdir("/Users/darren/Desktop/test"):
PYTHON FIND WORD IN FILE WITH RE HOW TO
In this tutorial I will show you how to list all files in a directory where those files start with a given string/prefix.