What are php and python? What are the differences between the two? Which one is better, php or Python? I believe many friends will have this problem. This chapter will tell you what are the differences between php and python? Introduction to application and grammatical differences. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.
1. What are php and python?
PHP is a general open source scripting language. The grammar absorbs the characteristics of C language, Java and Perl, which is easy to learn and widely used.
Python is a structured and powerful object-oriented programming language, similar to Perl, Ruby, Scheme, and Java.
2. Comparison between php and python
1. The difference between php and Python applications
php is mainly used in the field of web development.
Python is mainly used for system operation and maintenance, monitoring, crawlers, queue tasks, etc. Therefore, Python is easier to use outside the field of web development.
2. The (partial) difference between php and Python syntax
PHP’s syntax looks like it has not been carefully designed and is very casual. Some syntaxes seem very convenient (use dots to connect strings), but they cause a lot of trouble for later expansion (dots cannot be used to access members of objects), and another example is the rather painful namespace syntax. Python is better in comparison, but there are some incompatible syntax changes between Python2 and Python3.
1), output syntax:
PHP: echo can output multiple variables; print () only outputs one variable, and the return value is 1 on success and 0 on failure; print_r() only Output an array; die() outputs first, then shuts down; printf() formats the output string; var_dump() can determine the type and length of a variable and output the value of the variable.
Python: print defaults to newline , add commas without line breaks
2) Define data types:
PHP: seven data types: String, Integer, Float, Boolean, Array, Object, NULL.
Python: Five standard data types: Number, String, List, Tuple, Dictionary, where Number includes int, long, float, and complex.
3), define variables and methods:
PHP: Weakly typed language, use $ to define variables. Generally, variables must be referenced with $ (different from Java). When defining variables in a class, var must be added, and when defining methods, function test (){} must be declared with function.
Python: Weakly typed language, write directly when defining variables, no need to add anything else except access permission modifiers. When defining a method def __init__(self,name): ? To declare with def, self is a constant that must be added to represent the object of this class. The method body does not need {} and is written under:? ? Python uses indentation to determine the method content.
4), comments:
Single-line comments and multi-line comments
PHP: Use //, /* */
Python: #,'' ' ''' Multi-line comments can also be used as multi-line text, depending on their specific location
5), string variable concatenation:
PHP . (English period)
Python, (English comma) You can also use the placeholder % (just call it this name) For example: print "%s owns %d computers" %(a,b) ------a.b is a variable
6), encoding:
PHP:
header('content-type:text/html;charset=utf-8');
Python:
#encoding=utf-8 or #coding:utf-8 in order to highlight the program Great artistic talents often write # -*- coding:utf-8 -*- python3 defaults to utf-8
7), array operations:
Create array
PHP:
$array = new array();
or
$array = array("a"=>"A","b"=>"B");
Python:
array = []
or
array = [1,2,3]
Add array
PHP:
array_push($arr, $val);
Python:
array.append(val) #追加
or
array.extend(val) #合并
Delete array elements
PHP:
array_pop(); Delete the last element
array_shift(); delete the first element
Python:
array.pop()
3. How to call python program in PHP
php is far less powerful than python in many aspects, but in the web development process, there is a lot of data that needs to be calculated, and we hope that they can be displayed on the web page in real time. This requires calling the python program in PHP.
The specific implementation steps are as follows:
1. First place the php files and python files in a directory. Or write the absolute path of the python program.
2. Pay attention to the read, write or execution permissions of the file
3. Modify the php location file: php.ini sudo vim /etc/php5/apache2/php.ini Find disable_functions=…….; and delete the disabled pcntl_exec inside!
4. Restart apache2: sudo service apache2 restart 5. There may not be python in the user path used by the web server. When calling python in php, write the absolute address
Example:
python file
#!usr/bin/env python` #-*- coding:utf-8 -*- import sys import time ......
php file
<html> <head> <meta -----> <?php $program="/usr/bin/python ./astro.py"; #注意使用绝对路径 exec ($program); ?> </head> </html>
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