Python

1. Simple Regular ExpressionsImport res=r'abc're.findall (S,"aaaaaaaaaaaaaaa" # results for []Re.findall (S,"abcaaaaaaaaaaaa") # results for [' ABC ']re.findall (S,"abcaaaaaabcaaaa") # The result is [' abc ', ' abc ']2, Meta-character[]:

1, the general definition of statement characteristics: they change things.2. You can use variables to refer to functions.3, Nan:not a number (non-numeric)4. str function: Converts a value into a reasonable form of a string, the Repr function

official Python document: https://www.python.org/dev/peps/pep-0008/Code style: Use 4 empty Glyd to indicate indentation, preferably not using tab, and not to mix the two Wrap at least one line between functions Wrapping at least two

Tag:python    Optimization     object     #-*-Coding:utf-8-*-## def displaynumtype (num): # print num, ' is ', # if type (num) = = Type (0): # print ' an Integer ' # elif type (num) = = Type (0L): # print ' A long ' # elif type (num) = = Type (0.0):

In Python, a variable is marked or pointed to a value. When a variable is encountered, Python replaces it with a pointer to a value.>>> cost=2.99>>>. 1*cost0.29900000000000004Variable naming rules: The length of the variable name is

#-*-Coding:utf-8-*-__author__ = ' xy ' #切片 (slice) Extension Usage # # # # of slices with a step index to expand # Slice[1:2:3] where the 3rd position represents the step size, the default is # Simple str flip: s = ' ABCDE ' Print s[::-1]# >>> '

This function is to implement a tuple list iteration from multiple sequences, that is, to get an item from each sequence, and then to generate a tuple of all the items, and then return those tuple-generated lists. If there are multiple sequences,

Originally want to share some knowledge, but found, write write, feel share some experience, perhaps less let everyone go some detours, simply put the title of a change.I do not teach you what, I am not qualified, I am also stones, I just in the

#升级前必须先安装其它依赖Yum install readline-devel sqlite-devel bzip2-devel openssl-devel gdbm-devel libdbi-devel ncurses-libs zlib-devel-y#下载python安装包wget https:www.python.org/ftp/python/2.7.6/Python-2.7.6. Tgztar-ZXVF Python-2.7.6. TGZCD

System Programming: Provides API (Application programming Interface application programming Interface), can facilitate system maintenance and management, Linux under one of the iconic languages, is the ideal programming tool for many system

Libxml/xmlversion.h:no such file or directory sudo Install Libxml2-dev Libxslt1-dev Environmenterror:mysql_config not found sudo Install Libmysqlclient-dev Numpy.distutils.system_info. Notfounderror:no Lapack/blas

Abnormal Exception handling Catching exceptions Throw exception Custom exceptions Some of the common exceptions Exception handling catches exceptions try/exceptSimilar to catching

Define a web crawlerWeb Spider, also known as Spider, Network robot, also known as Web Chaser. According to certain rules, the program or script of the dimension network information. Other infrequently used names are ants, self-indexing, simulation

Learning Python was meant to be fun, but it was found that the language was as simple as people's, so that the block was close to human language, which brought great benefits to the developers themselves.Anyway is learning to play, I will start from

Processes and ThreadsIn multitasking, each task has its own process, and a task has many subtasks that open threads in the process to perform these subtasks. In general, you can run the base unit of a separate dispatch and allocation as a thread,

Find the nth element in the sequence (implemented by the partition function) and the partition Function Partition is a segmentation algorithm used to divide a sequence a [n] into three parts: a [n] is greater than the part of an element x, equal to

Common methods in the time module of Python, pythontime In the process of application development, it is inevitable to deal with date and time processing. For example, record the execution time of a complex algorithm and the delay of packets in

Interaction between Python Web. py and AJAX If you haven't written a Blog for a long time, you may be lazy or feel that you have written something quite low before, and you are not too eager to write a Blog. The practical training has already

Python MD5 Encryption The following describes how to use the Python built-in hash library to encrypt strings using MD5: First, import the modules required for MD5 encryption:   Import hashlib Then create an md5 object:     M = hashlib. md5 ()

Python local and global namespace usage instance, python global namespace This example describes the usage of local and global namespaces in Python. Share it with you for your reference. The details are as follows: X = 1def fun (a): B = 3 x = 4