Slides from the training on the topic "Python Programming Essentials"

1. http://www.skillbrew.com
/Skillbrew
Talent brewed by the
industry itself
Python interpreter and files
Pavan Verma
@YinYangPavan
Founder, P3 InfoTech Solutions Pvt. Ltd.
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Python Programming Essentials

2. © SkillBrew http://skillbrew.com
Interpreter
 An interpreter is a computer program
which executes other programs.
 Python interpreter carries out
instructions in your program.
 Python interpreter can be used
interactively to test out instructions on
the fly. A good way to try little
experiments.
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3. © SkillBrew http://skillbrew.com
>>> 'hey' * 2
'heyhey'
>>> 2 + 2
4
>>> 9/2
4
>>> 9//2
4
>>> colors = ['orange', 'red',
'yellow']
>>> colors
['orange', 'red', 'yellow']
>>> for color in colors:
color
'orange'
'red'
'yellow'
Try things in interpreter
and it will give back
results immediately. No
need to write separate
programs to learn new
features.
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4. © SkillBrew http://skillbrew.com
pyc files
.pyc files are "Compiled" Python files”. Once a file is
compiled, Python executes the compiled file.
.pyc files are created when the .py file’s modification
time is different.
It’s good to keep .pyc files around, speeds up execution
when a program is ran again by avoiding compilation.
Python
File
*.py
Bytecode
*.pyc
Interpreter
uses *.pyc
file
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5. © SkillBrew http://skillbrew.com
A look under the hood
 The python interpreter consists of two parts:
• A python bytecode compiler
• A virtual machine which executes Python
bytecode.
Source:
http://trizpug.org/Members/cbc/
wyntkap/compiler.html 5

6. © SkillBrew http://skillbrew.com
A look under the hood (2)
• The bytecode compiler accept human
readable python expressions and statements
as input.
• And produces machine-readable python
bytecode as output.
Source:
http://trizpug.org/Members/cbc/
wyntkap/compiler.html 6

7. © SkillBrew http://skillbrew.com
A look under the hood (3)
• The virtual machine accepts the python
bytecode as input.
• And executes the virtual machine
instructions represented by the bytecode.
Source:
http://trizpug.org/Members/cbc/
wyntkap/compiler.html 7

8. © SkillBrew http://skillbrew.com
Resources
 http://trizpug.org/Members/cbc/wyntka
p/compiler.html
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