<< Chapter < Page Chapter >> Page >

Setting the path with a batch file

Listing 1 shows the contents of a batch file named 1359-1050-01.bat containing four commands that :

  1. Reduce the clutter on the output screen (echo off) .
  2. Temporarily set the path to the location of the file named python.exe on my computer.
  3. Attempt to execute the Python script file named 1359-1050-01.py, which will be discussed later in this module.
  4. Pause onscreen and wait to be dismissed with the prompt "Press any key to continue . . ."
Listing 1 . Setting the path temporarily with a batch file.
echo off path=%path%;"C:\Program Files (x86)\Python34"python 1359-1050-01.py pause

The second command in Listing 1 is the important command for thissection of this module. It will temporarily set the path to the indicated folder. If you elect to use this approach, you will need toreplace the text inside the double quotes with the path to the folder containing the file named python.exe on your computer.

This approach appends the new path onto the environment variable named path on a temporary basis. It goes away as soon as you respond to the pause statement at the end or otherwise close the command-line window that appears when you execute the batch file.

Create a script file

Once you have the path variable properly set, or you know how to set it temporarily in a batch file, use the text editor of your choice andcreate a file named 1359-1050-01.py that contains the Python programming statements shown in Listing 2 . (You can give the file any name that you chooseprovided that the extension is .py and provided that you properly reflect the name in the third line of the batch file shown in Listing 1 .)

Listing 2 . Contents of the file named 1359-1050-01.py.
a=2 b=3a=2*a b=3*bc=a+b print(c)

You should recognize all of the statements in Listing 2 . Note, however, that in a script, they are not preceded by an interactive prompt (>>>).

Store this file in any folder on your hard drive. You may want to create a new directory for the sole purpose of storing Python script files.

Then create the corresponding batch file with the contents shown in Listing 1 and save it in the same folder as the script file. (If you have permanently set your path to support Python, you can omit the path command in Listing 1 .)

Run your script file

Once you have accomplished the above, double-click the batch file to execute it. The batch file will temporarily set the path and attempt to run your script.If all goes well, a command-line window will appear on your screen with contents similar to that shown in Figure 1 . (Note that I deleted some of the text on the first line for brevity. Your first line will be different anyway.)

Figure 1 . Screen output from running the script named 1359-1050-01.py.
M:\Baldwin\AA-School\...>echo off 13Press any key to continue . . .

The correct output

If you go back to the script file in Listing 2 and do the arithmetic, you will see that the output value of 13 produced by the program is correct.

If you got an output value of 13, -- congratulations -- you have just written and executed your first Python script. If not, try to figure out why.

Questions & Answers

Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
Kate Reply
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Kate Reply
what is the change in momentum of a body?
Eunice Reply
what is a capacitor?
Raymond Reply
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
Maria Reply
please solve
Sharon
8m/s²
Aishat
What is Thermodynamics
Muordit
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
Saheed Reply
50 m/s due south east
Someone
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
Ramon Reply
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
Someone
definitely of physics
Haryormhidey Reply
how many start and codon
Esrael Reply
what is field
Felix Reply
physics, biology and chemistry this is my Field
ALIYU
field is a region of space under the influence of some physical properties
Collete
what is ogarnic chemistry
WISDOM Reply
determine the slope giving that 3y+ 2x-14=0
WISDOM
Another formula for Acceleration
Belty Reply
a=v/t. a=f/m a
IHUMA
innocent
Adah
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
Nassze Reply
how do lnternal energy measures
Esrael
Two bodies attract each other electrically. Do they both have to be charged? Answer the same question if the bodies repel one another.
JALLAH Reply
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you. Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Robert
like charges repel while unlike charges atttact
Raymond
What is specific heat capacity
Destiny Reply
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Itse 1359 introduction to scripting languages: python. OpenStax CNX. Jan 22, 2016 Download for free at https://legacy.cnx.org/content/col11713/1.32
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Itse 1359 introduction to scripting languages: python' conversation and receive update notifications?

Ask