Why do I get syntax error when I try to do a pip install on CentOS 6?

I’m trying to install a python module called cymysql on a CentOS 6 system by commands like

yum install -y python-setuptools && easy_install pip && pip install cymysql

However I received an Error message saying there’re a few lines got SyntaxError: invalid syntax ( see the error code as following)—It actually happened when I run the third command pip install cymysql

Traceback (most recent call last):
  File "/usr/local/bin/pip", line 11, in <module>
    load_entry_point('pip==21.0', 'console_scripts', 'pip')()
  File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 561, in load_entry_point
  File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2631, in load_entry_point
  File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2291, in load
  File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2297, in resolve
  File "/usr/local/lib/python2.7/site-packages/pip-21.0-py2.7.egg/pip/_internal/cli/main.py", line 60
    sys.stderr.write(f"ERROR: {exc}")
                               ^
SyntaxError: invalid syntax

Not so sure what’s happening here, just wondering if anyone can help? (I enclosed the pip file and main.py here but I don’t know where is the init.py file).BTW, It’s centOS 6 but I have installed the Python 3.6.10 on the server.When I run the command python3.6 -V, I got

python3.6.10

FIY

PIP file Code:

 #!/usr/bin/python
 # EASY-INSTALL-ENTRY-SCRIPT: 'pip==21.0','console_scripts','pip'
 __requires__ = 'pip==21.0'
 import re
 import sys
 from pkg_resources import load_entry_point

 if __name__ == '__main__':
   sys.argv[0] = re.sub(r'(-script.pyw?|.exe)?$', '', sys.argv[0])
   sys.exit(
       load_entry_point('pip==21.0', 'console_scripts', 'pip')()  //**THIS IS LINE 11**
   )

Line 57 to 62 in Main.py

try:
    cmd_name, cmd_args = parse_command(args)
except PipError as exc:
    sys.stderr.write(f"ERROR: {exc}")  //**THIS IS LINE 60**
    sys.stderr.write(os.linesep)
    sys.exit(1)