python3
sudo apt-get install python3-pip
python2
sudo apt-get install python-pip
If it still does not work, follow the steps below
Reason: The -with-secure-path option was added when compiling sudo.
Solution: add an alias to the environment configuration file
(1) vi ~/.bashrc
Add the following content:
alias sudo=’sudo env PATH=$PATH’
(2) source ~/.bashrc
I used the requests.get()method when writing a crawler in python :
DEF OpenURL (URL, IP, Agent):
# function parameter is url: web page address; ip: ip pool; agent: User-Agent, three are string type
requests.get (url, headers = agent, proxies = ip)
What is puzzled is that the’str’ object has no attribute’get’ error was reported when using it
After reviewing the documentation, it was found that the headers and proxies parameters in the get() method should be passed in a dictionary instead of a string , so after modification, the code runs successfully:
def openUrl(url, ip, agent):
headers = { ' User-Agent ' : agent}
proxies = { ' http ' : ip}
requests.get(url, headers =headers, proxies=proxies)
1. There are some differences between Python 3.X and python 2.X. I encountered two problems as follows:
a. First report: mysqlclient version 1.3 is wrong:
Solution: comment out the line
b. Second, the problem of character set
The error is as follows: file “C:// users/administrator/pcharmprojects/untitled1/venv/lib/site packages/Django/db/backends/MySQL/operations. Py”, line 146, in last_ executed_ query
query = query.decode(errors=’replace’)
AttributeError: ‘str’ object has no attribute ‘decode’
Solution: Comment out here because the character set is not supported
Python sends e-mail. The 126 e-mail box used before is normal, but today it is changed to Hotmail, and this error has been reported all the time
smtplib.SMTPE xception:SMTPAUTHextensionnotsupportedbyserver
my previous code is as follows:
def sendmail(receivers,mailtitle,mailcontent):
ret=True
# try:
# msg=MIMEText(mailcontent,'plain','utf-8')
msg = MIMEText(mailcontent, 'html', 'utf-8')
msg['From']=formataddr(["I'm Black",sender]) # brackets correspond to sender's email nickname, sender's email account
# msg['To']=formataddr(["Recipient nickname",receivers]) # The one in brackets corresponds to the recipient's email nickname, recipient's email account
msg['Subject']=mailtitle # The subject of the message, also known as the title
server = None
# Determine if it is an SSL connection
if flag_mail_ssl:
server=smtplib.SMTP_SSL(mail_host, mail_port) # SMTP server in sender's mailbox
else:
server=smtplib.SMTP(mail_host, mail_port)#
server.login(mail_user, mail_pass) # the brackets correspond to the sender's mailbox account, mailbox password
server.sendmail(sender,receivers,msg.as_string()) # The brackets correspond to the sender's mailbox account, the recipient's mailbox account, and the sent mail
server.quit()# close the connection
# except Exception as e:# If the statement in try is not executed, the following ret=False will be executed
# ret=False
return retAfter searching the Internet, add the following two lines of code before login:
server.ehlo() # Send SMTP 'ehlo' command to Gamil
server.starttls()That’s it. The final code is:
def sendmail(receivers,mailtitle,mailcontent):
ret=True
# try:
# msg=MIMEText(mailcontent,'plain','utf-8')
msg = MIMEText(mailcontent, 'html', 'utf-8')
msg['From']=formataddr(["I'm Black",sender]) # brackets correspond to sender's email nickname, sender's email account
# msg['To']=formataddr(["Recipient nickname",receivers]) # The one in brackets corresponds to the recipient's email nickname, recipient's email account
msg['Subject']=mailtitle # The subject of the message, also known as the title
server = None
# Determine if it is an SSL connection
if flag_mail_ssl:
server=smtplib.SMTP_SSL(mail_host, mail_port) # SMTP server in sender's mailbox
else:
server=smtplib.SMTP(mail_host, mail_port)#
server.ehlo() # Send SMTP 'ehlo' command to Gamil
server.starttls()
server.login(mail_user, mail_pass) # The corresponding mailbox account and mailbox password in parentheses is the sender's mailbox
server.sendmail(sender,receivers,msg.as_string()) # The mail accounts in parentheses are the sender's mailbox account, the recipient's mailbox account, and the sent mail
server.quit()# close the connection
# except Exception as e:# If the statement in try is not executed, the following will be executed ret=False
# ret=False
return ret
How to solve python Installation WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.1. Install the relevant dependencies
yum install gcc libffi-devel zlib* openssl-devel
# libffi-devel zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make
2. Download and unzip
wget https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tar.xz
# Download
wget https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tar.xz
# Unzip and compile.
tar -xvJf Python-3.7.1.tar.xz
cd Python-3.7.1
3. Compile and install
. /configure prefix=/usr/local/python3
make && make install
# After compiling, create a softlink file to the executable path.
ln -s /usr/local/python3/bin/python3 /usr/bin/python3
ln -s /usr/local/python3/bin/pip3 /usr/bin/pip3
# We can clear the previously compiled executables and configuration files && Clear all generated files:.
make clean && make distclean
bug: Failed to use pip command
2.1 Error messages
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting virtualenv
Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)’: /simple/virtualenv/
Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)’: /simple/virtualenv/
Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)’: /simple/virtualenv/
Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)’: /simple/virtualenv/
Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by ‘SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)’: /simple/virtualenv/
Could not fetch URL https://pypi.org/simple/virtualenv/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host=’pypi.org’, port=443): Max retries exceeded with url: /simple/virtualenv/ (Caused by SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)) – skipping
Could not find a version that satisfies the requirement virtualenv (from versions: )
No matching distribution found for virtualenv
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Could not fetch URL https://pypi.org/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host=’pypi.org’, port=443): Max retries exceeded with url: /simple/pip/ (Caused by SSLError(“Can’t connect to HTTPS URL because the SSL module is not available.”)) – skipping
2.2 Reason
System version centos6.5, where openssl version is OpenSSL 1.0.1e-fips 11 Feb 2013, and python3.7 needs openssl version 1.0.2 or 1.1.x, need to upgrade openssl and recompile python3.7.0. The version of openssl installed by yum is relatively low.
2.3 Upgrade openssl
# 1. download openssl
wget https://www.openssl.org/source/openssl-1.1.1a.tar.gz
tar -zxvf openssl-1.1.1a.tar.gz
cd openssl-1.1.1a
# 2.Compile and install
. /config –prefix=/usr/local/openssl no-zlib #no-zlib
make
make install
# 3.Back up the original configuration
mv /usr/bin/openssl /usr/bin/openssl.bak
mv /usr/include/openssl/ /usr/include/openssl.bak
# 4. New version configuration
ln -s /usr/local/openssl/include/openssl /usr/include/openssl
ln -s /usr/local/openssl/lib/libssl.so.1.1 /usr/local/lib64/libssl.so
ln -s /usr/local/openssl/bin/openssl /usr/bin/openssl
# 5. Modify the system configuration
## Write the search path of the openssl library file
echo “/usr/local/openssl/lib” >> /etc/ld.so.conf
## To make the modified /etc/ld.so.conf take effect
ldconfig -v
# 6. Check the openssl version
openssl version
openssl version note:
/usr/local/openssl/bin/openssl: error while loading shared libraries: libssl.so.1.1: cannot open shared object file: No such file or directory
If your libssl.so.1.1 file is under /usr/local/openssl/lib/, you can do this
ln -s /usr/local/openssl/lib/libssl.so.1.1 /usr/lib64/libssl.so.1.1
ln -s /usr/local/openssl/lib/libcrypto.so.1.1 /usr/lib64/libcrypto.so.1.1
3.3 reinstall python
./configure –prefix=/usr/local/python3 –with-openssl=/usr/local/openssl
make
make install
Error：
Today, when I write a simple Python class definition code, I encountered the problem of reporting an error: typeerror: drive() takes 2 positional arguments but 3 were given
The code is as follows
class Car:
speed = 0
def drive(self,distance):
time = distance/self.speed
print(time)
bike = Car()
bike.speed=60
bike.drive(60,80)After investigation, it was found that it was the self parameter in the def drive (self, distance) method in the class definition
Now let’s take a brief look at the basic information of self in Python
self , which means that the created class instance itself and the method itself can bind various attributes to self, because self points to the created instance itself. When creating an instance, you can’t pass in empty parameters. You must pass in parameters that match the method, but you don’t need to pass in self. The Python interpreter will pass in instance variables by itself
so there are two solutions
method 1: transfer only one parameter. If you want to transfer two parameters, look at method 2
class Car:
speed = 0
def drive(self,distance):
time = distance/self.speed
print(time)
bike = Car()
bike.speed=60
bike.drive(80)Method 2:
class Car:
speed = 0
def drive(self,distance,speed):
time = distance/speed
print(time)
bike = Car()
bike.drive(80,50)When building the automation framework, I encountered a problem, as shown in the following figure:
According to the meaning of the error, it should be the problem of the __init__ function, and the location should be the HomePage file.
Go and check the file immediately, as shown in the figure:
It turned out to be careless __init__ (self)
after passing in one less parameter driver , you still have to be careful
Solution:
def init (self, driver): just add the parameter driver
PEP 328 Relative Imports and __name__ states:
Relative imports use a module’s __name__ attribute to determine that module’s position in the package hierarchy. If the module’s name does not contain any package information (e.g. it is set to ‘__main__’) then relative imports are resolved as if the module were a top level module, regardless of where the module is actually located on the file system.
That is: relative import in the package hierarchy, use the __name__ attribute of the module to get the location of the module. But if the name of the module does not contain any package information (for example, __main__ module), regardless of whether the module is actually located in the file system, relative imports will be imported as a top level module.
According to the recommendations of 6.4.2. Intra-package References :
Note that relative imports are based on the name of the current module. Since the name of the main module is always “__main__”, modules intended for use as the main module of a Python application must always use absolute imports.
__mian__ use Absolute importmanner, while still using other modulesRelative Import
if __name__ == '__main__':
sys.path.append(os.path.dirname(sys.path[0]))
Refer to stackoverflow vaultah’s answer, which is more detailed, so I won’t repeat it here.
PEP 328 Rationale for Relative Imports states:
Several use cases were presented, the most important of which is being able to rearrange the structure of large packages without having to edit sub-packages.In addition, a module inside a package can’t easily import itself without relative imports.
That is: relative import can rebuild large python packages without re-editing sub-packages; in addition, relative import can import itself relatively easily.
#Another type of error
SyntaxError: Missing parentheses in call to 'print'. Did you mean print(The format of the code is as follows:
print "File %s not exist" % filename
。。。
print '-------xxx------'
change to
print ("File %s not exist" % filename)
print ('-------xxx------')The error is shown in the figure:
The solution is as follows:
