Philip Joyce - C and Python Applications: Embedding Python Code in C Programs, SQL Methods, and Python Sockets

Philip Joyce

C and Python Applications

Embedding Python Code in C Programs, SQL Methods, and Python Sockets

1st ed.

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Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub via the books product page, located at www.apress.com/9781484277737. For more detailed information, please visit http://www.apress.com/source-code.

About the Author

Philip Joyce

has 28 years of experience as a software engineer, working on control of steel production, control of oil refineries, communications software (pre-Internet), office products (server software), and computer control of airports. He programs in Assembler, COBOL, Coral 66, C, and C++ with SQL. He served as a mentor to new graduates in the Ferranti Company. He obtained an MSc in computational physics (including augmented matrix techniques and Monte Carlo techniques using Fortran) from Salford University in 1996. He is also a chartered physicist and a member of the Institute of Physics (member of the Higher Education Group).

About the Technical Reviewer

Swathi Sutrave

is a self-professed tech geek. She has been a subject matter expert for several different programming languages, including Python, C, and SQL, for corporations, startups, and universities.

This is the first of two chapters in which youll review both Python and C programming languages. A basic understanding of computing and what programs are about is assumed although no prior knowledge of either Python or C is needed.

In this chapter, we will start with the basics of Python. This will include how items used in a program are stored in the computer, basic arithmetic formats, handling strings of characters, reading in data that the user can enter on the command line, etc. Then we will work up to file access on the computer, which will lead us up to industrial/commercial-level computing by the end of the book.

If you dont already have a Python development environment on your computer, you can download it and the Development Kit, free of charge, from www.python.org/downloads/ . Another way you can access Python is by using Visual Studio. Again, a version of this can be downloaded.

This section looks at the different types of store areas that are used in Python. We refer to these store areas as variables . The different types can be numbers (integers or decimals), characters, and different types of groups of these (strings, arrays, dictionaries, lists, or tuples).

In these examples, you can go to the command line and enter Python which starts up the Python environment and produces >>> as the prompt for you to enter Python code.

Here we are defining a variable called a1 and we are assigning the integer value 51 to it.

We then call the function print with the parameter type and a1 and we get the reply class int. type means that we want to display whether the variable is an integer, floating point, character, string, etc.

We can now exit the Python environment by typing quit().

We will now perform the same function from a program.

Create a file called typ1a.py.

Now on the command line, enter python typ1a.py.

which is the same as our first example.

This is just demonstrating the equivalence of the two methods.

Obviously, if you want to run a program with many lines of code and possibly run it many times, then having the code in a file is more efficient.

The 51 entered is an int. The 51.6 is a float (decimal) type, and 51 is a string.

We can make the results a little clearer if we use print(a1 is, type(a1)).