Chapter 1.2 Scrapy installation __python in the python2 of Scrapy

Python version uses 3.5.2, performs pip install Scrapy, prompts error:unable to find Vcvarsall.bat error, yellow content is lower than the PIP version, you can perform
Python-m The PIP install--upgrade pip is upgraded

python3.5 is dependent on VS2015 in the Windows environment, and VS2015 is for Win10 and cannot be uploaded in Win7. python3.4 in Windows environment relies on vs2013,vs2013 requirements for Win7 patching. Think about why you want to upgrade Python, but also rely on the VS environment, laborious, many Linux, Mac installed by default are Python2 version, the scientists use Python for many years, they do not focus on the algorithm, do not constantly follow the upgrade Python, the significance. The final choice Python version is 2.7.12, I just need python to do what I want to do, as for the so-called Chinese parsing defects, there can be other means to make up.
Execute into the scrapy directory, execute python setup.py install, the following exception occurred:

Make sure the development packages of LIBXML2 and Libxslt ar E installed
Follow the instructions in lxml to install lxml for XML parsing.

Executes the python setup.py install again, prompting the error
Error:the ' PYASN1 ' distribution was not found and are required by service- Identity
After performing pip install PYASN1, install scrapy again, prompting for exceptions

BUILD\TEMP.WIN32-2.7\RELEASE\_OPENSSL.C (433): Fatal error C1083:cannot open in
clude file: ' Openssl/opensslv.h ': No such file or directory
error: [ERROR 5]: ' C:\\users\\dzm\\appdata\\local\\temp\\easy_install-wv1jmv\\c
Ryptography-1.5.2\\.eggs\\cffi-1.8.3-py2.7-win32.egg\\_cffi_backend.pyd '

Execute command PIP install cryptography, install encryption module
Install Scrapy again, finally installed successfully

According to the above process summary, as follows
1. scrapy's Download Address
2. Install lxml
3. Install PYASN1
4. Install cryptography
5. Final installation Scrapy