一直有看到网上有讨论Python2和Python3的比较，最近公司也在考虑是否在spark-python大数据开发环境中升级到python3。通过本篇博文记录Python2.7.13和Pthon3.5.3的各方面比较。

环境配置

这里继续使用我们在之前博文里配置的环境。
因为是比较Python2和Python3差异，所以单纯升级Python版本无法解决，我通过pyenv和virtualenv两个工具来实现隔离的测试环境。
参考文档：使用pyenv和virtualenv搭建python虚拟环境、使用 pyenv 可以在一个系统中安装多个python版本
配置的步骤如下：

• 最开始是更新Tkinter，不然后续要重新再来一次，不要问我为什么知道...

sudo yum install tkinter -y
sudo yum install tk-devel tcl-devel -y

• 更新pyenv依赖软件

sudo yum install readline readline-devel readline-static -y
yum install openssl openssl-devel openssl-static -y
yum install sqlite-devel -y
yum install bzip2-devel bzip2-libs -y

• 下载安装pyenv，并下载python2.7.13和python3.5.3

git clone https://github.com/yyuu/pyenv.git ~/.pyenv
chgmod 777 -R ~/.pyenv
echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.bash_profile
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.bash_profile
echo 'eval "$(pyenv init -)"' >> ~/.bash_profile
exec $SHELL
source ~/.bash_profile 

pyenv  install --list
pyenv install -v 2.7.13
pyenv install -v 3.5.3

• 下载安装pyenv-virtualenv，并安装两个隔离环境

git clone https://github.com/yyuu/pyenv-virtualenv.git ~/.pyenv/plugins/pyenv-virtualenv   
echo 'eval "$(pyenv virtualenv-init -)"' >> ~/.bash_profile
source ~/.bash_profile
pyenv virtualenv 2.7.13 py2
pyenv virtualenv 3.5.3 py3

好，到此基本搞定两个隔离的python环境，测试如下，我们可以发现当前的python环境从centos7默认的2.7.5切换到2.7.13再切换到3.5。

[kejun@localhost ~]$ python -V
Python 2.7.5
[kejun@localhost ~]$ pyenv activate py2
(py2) [kejun@localhost ~]$ python -V
Python 2.7.13
(py2) [kejun@localhost ~]$ pyenv deactivate
[kejun@localhost ~]$ pyenv activate py3
(py3) [kejun@localhost ~]$ python -V
Python 3.5.

详细测试：

我们安装了常用的数据分析第三方工具包，并做了安装测试和样例测试，样例测试的脚本见最下。

# encoding=utf-8
import sys
import platform
import traceback
import gc
import ctypes  

  
STD_OUTPUT_HANDLE= -11  
FOREGROUND_BLACK = 0x0  
FOREGROUND_BLUE = 0x01 # text color contains blue.  
FOREGROUND_GREEN= 0x02 # text color contains green.  
FOREGROUND_RED = 0x04 # text color contains red.  
FOREGROUND_INTENSITY = 0x08 # text color is intensified.  
  
class WinPrint:
    """
    提供给Windows打印彩色字体使用
    """

    std_out_handle = ctypes.windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)  
      
    def set_cmd_color(self, color, handle=std_out_handle):  
        bool = ctypes.windll.kernel32.SetConsoleTextAttribute(handle, color)  
        return bool  
      
    def reset_color(self):  
        self.set_cmd_color(FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE)  
      
    def print_red_text(self, print_text):  
        self.set_cmd_color(FOREGROUND_RED | FOREGROUND_INTENSITY)  
        print (print_text)  
        self.reset_color()  
          
    def print_green_text(self, print_text):  
        self.set_cmd_color(FOREGROUND_GREEN | FOREGROUND_INTENSITY)  
        print (print_text)  
        self.reset_color()  

class UnixPrint:
    """
    提供给Centos打印彩色字体
    """
    def print_red_text(self, print_text): 
        print('\033[1;31m%s\033[0m'%print_text)
    
    def print_green_text(self, print_text): 
        print('\033[1;32m%s\033[0m'%print_text)

py_env = "Python2" if sys.version.find("2.7") > -1 else "Python3"
sys_ver = "Windows" if platform.system().find("indows") > -1 else "Centos"
my_print = WinPrint() if platform.system().find("indows") > -1 else UnixPrint()


def check(sys_ver, py_env):
    """
    装饰器，统一输入输出
    顺便测试带参数的装饰器，非必须带参数
    """
    def _check(func):
        def __check():
            try:
                func()
                my_print.print_green_text(
                    "[%s,%s]: %s pass." % (sys_ver, py_env, func.__name__))
            except:
                traceback.print_exc()
                my_print.print_red_text(
                    "[%s,%s]: %s fail." % (sys_ver, py_env, func.__name__))
        return __check
    return _check


def make_requirement(filepath, filename):
    """
    处理pip requirements文件
    """
    result = []
    with open(filepath + "\\" + filename, "r") as f:
        data = f.readlines()

        for line in data:
            if line.find("==") > -1:
                result.append(line.split("==")[0] + "\n")
            else:
                result.append(line + "\n")
    with open(filepath + "\\" + filename.split(".")[0] + "-clean.txt",
              "w") as f1:
        f1.writelines(result)


@check(sys_ver, py_env)
def test_scrapy():
    from scrapy import signals
    from selenium import webdriver
    from scrapy.http import HtmlResponse
    from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
    from selenium.webdriver.common.keys import Keys
    from selenium.common.exceptions import NoSuchElementException
    from selenium.common.exceptions import TimeoutException
    from selenium.webdriver.support import expected_conditions as EC
    from selenium.webdriver.common.by import By
    from selenium.webdriver.support.ui import WebDriverWait


@check(sys_ver, py_env)
def test_matplotlib():
    import matplotlib.pyplot as plt
    l = [1, 2, 3, 4, 5]
    h = [20, 14, 38, 27, 9]
    w = [0.1, 0.2, 0.3, 0.4, 0.5]
    b = [1, 2, 3, 4, 5]
    fig = plt.figure()
    ax = fig.add_subplot(111)
    rects = ax.bar(l, h, w, b)
    # plt.show()


@check(sys_ver, py_env)
def test_beautifulSoup():
    from bs4 import BeautifulSoup
    html_str = "<html><meta/><head><title>Hello</title></head><body onload=crash()>Hi all<p></html>"
    soup = BeautifulSoup(html_str, "lxml")
    # print (soup.get_text())


@check(sys_ver, py_env)
def test_lxml():
    from lxml import html
    html_str = "<html><meta/><head><title>Hello</title></head><body onload=crash()>Hi all<p></html>"
    html.fromstring(html_str)


@check(sys_ver, py_env)
def test_xls():
    import xlrd
    import xlwt
    from xlutils.copy import copy
    excel_book2 = xlwt.Workbook()
    del excel_book2
    excel_book1 = xlrd.open_workbook("1.xlsx")
    del excel_book1
    import docx
    doc = docx.Document("1.docx")
    # print (doc)
    del doc
    gc.collect()


@check(sys_ver, py_env)
def test_data_analysis():
    import pandas as pd
    import numpy as np
    data_list = np.array([x for x in range(100)])
    data_serial = pd.Series(data_list)
    # print (data_serial)
    from scipy import fft
    b = fft(data_list)
    # print (b)


@check(sys_ver, py_env)
def test_statsmodels():
    import statsmodels.api as sm
    data = sm.datasets.spector.load()
    data.exog = sm.add_constant(data.exog, prepend=False)
    # print data.exog


@check(sys_ver, py_env)
def test_sklearn():
    from sklearn import datasets
    iris = datasets.load_iris()
    data = iris.data
    # print(data.shape)


@check(sys_ver, py_env)
def test_gensim():
    import warnings
    warnings.filterwarnings(action='ignore', category=UserWarning, module='gensim')
    from gensim import corpora
    from collections import defaultdict
    documents = ["Human machine interface for lab abc computer applications",
                 "A survey of user opinion of computer system response time",
                 "The EPS user interface management system",
                 "System and human system engineering testing of EPS",
                 "Relation of user perceived response time to error measurement",
                 "The generation of random binary unordered trees",
                 "The intersection graph of paths in trees",
                 "Graph minors IV Widths of trees and well quasi ordering",
                 "Graph minors A survey"]
    stoplist = set('for a of the and to in'.split())
    texts = [[word for word in document.lower().split() if word not in stoplist]
             for document in documents]
    frequency = defaultdict(int)
    for text in texts:
        for token in text:
            frequency[token] += 1
    texts = [[token for token in text if frequency[token] > 1]
             for text in texts]
    dictionary = corpora.Dictionary(texts)
    dictionary.save('deerwester.dict')


@check(sys_ver, py_env)
def test_jieba():
    import jieba
    seg_list = jieba.cut("我来到了北京参观天安门。", cut_all=False)
    # print("Default Mode: " + "/ ".join(seg_list))  # 精确模式


@check(sys_ver, py_env)
def test_mysql():
    import MySQLdb as mysql
    #测试pet_shop连接
    db = mysql.connect(host="xx", user="yy", passwd="12345678", db="zz")
    cur = db.cursor()
    sql="select id from role;"
    cur.execute(sql)
    result = cur.fetchall()
    db.close()
    # print (result)


@check(sys_ver, py_env)
def test_SQLAlchemy():
    from sqlalchemy import Column, String, create_engine,Integer
    from sqlalchemy.orm import sessionmaker
    from sqlalchemy.ext.declarative import declarative_base
    engine = create_engine('mysql://xxx/yy',echo=False)
    DBSession = sessionmaker(bind=engine)
    Base = declarative_base()
    class rule(Base):
        __tablename__="role"
        id=Column(Integer,primary_key=True,autoincrement=True)
        role_name=Column(String(100))
        role_desc=Column(String(255))
    new_rule=rule(role_name="test_sqlalchemy",role_desc="forP2&P3")
    session=DBSession()
    session.add(new_rule)
    session.commit()
    session.close()


@check(sys_ver, py_env)
def test_redis():
    import redis 
    pool = redis.Redis(host='127.0.0.1', port=6379) 

@check(sys_ver, py_env)
def test_requests():
    import requests
    r=requests.get(url="http://www.cnblogs.com/kendrick/")
    # print (r.status_code)


@check(sys_ver, py_env)
def test_PyMongo():
    from pymongo import MongoClient
    conn=MongoClient("localhost",27017)

if __name__ == "__main__":
    print ("[%s,%s]  start checking..." % (sys_ver, py_env))
    test_scrapy()
    test_beautifulSoup()
    test_lxml()
    test_matplotlib()
    test_xls()
    test_data_analysis()
    test_sklearn()
    test_mysql()
    test_SQLAlchemy()
    test_PyMongo()
    test_gensim()
    test_jieba()
    test_redis()
    test_requests()
    test_statsmodels()
    print ("[%s,%s]  finish checking." % (sys_ver, py_env))