Programmer Group

Operating system interface The os module provides many functions associated with the operating system. >>> import os >>> os.getcwd() # Returns the current working directory 'C:\\Python34' >>> os.chdir('/server/accesslogs') # Modify the current working directory >>> os.system('mkdir today') # Ex ...

catalogue 1. Known array var stringArray = ["This", "is", "Baidu", "Campus"] 2. The string foo = "get element by ID" is known. Write function to convert it into hump representation 3. Known array var numberArray = [3,6,2,4,1,5]; Apply array API for operation 4. Output today's date in YYYY-MM ...

1. Common Nginx regular expressions It's also mentioned in the blog before the rule, and it's important to mention it here. ^ : Matches the starting position of the input string $ : Match end position of input string * : Match the previous character zero or more times. Such as " ol*"Can match " o"And " ol","oll" + : Match t ...

1. Show / etc/passwd Lines in the file that do not end with / bin/bash; grep -v "/bin/bash$" /etc/passwd 2. Find the two or three digits in the / etc/passwd file; grep -E '\<[0-9]{2,3}\>' /etc/passwd 3. Find the line in the / etc/rc.d/rc.sysinit or / etc/grub2.cfg file that starts with at least one white space character and is foll ...

        Mengxin records his learning experience in some days. preface:          The teacher sent me the corrected experimental report (. pdf) at noon. As a teacher assistant, I need to return each report to the corresponding students and register my grades. There are 5 + reports and ...

 regular expressions are powerful tools and techniques for string processing.  regular expression uses a predefined pattern to match a class of strings with common characteristics. It is mainly used to process strings. It can quickly and accurately complete complex search, replacement and other processing requirements. It has important appli ...

js regular expression learning 1. What is a regular expression? Regular expressions describe the composition pattern of strings and are often used to check whether strings meet predetermined format requirements **Regular expressions describe rules bit by bit: * * it describes the form of strings bit by bit <script> // Cr ...

Title Description Farmer John's cows were very excited when they learned that they were celebrating the year of the ox recently. The year of the ox is always the favorite of dairy cows. We know that the zodiac corresponding to each year in the Chinese calendar follows a 12-year cycle: ox, tiger, rabbit, dragon, snake, horse, pig, rat (ox, tig ...

easypoi import verification 1, Basic verification of import Now the product needs to verify the imported Excel. Illegal Excel is not allowed to be warehoused. You need to return specific error information to the front end and prompt the user. The error information needs to include line number and corresponding error. Because EasyPOI supports ...

The java.util.regex package supports regular representation and includes two classes, Pattern (pattern class) and Matcher (matcher class). The Patterns class is the object used to express and state the search pattern used, and the Matcher class is the object that really affects the search. 1 Static method for checking strings To determine if ...