Engfmt(Engineering Format) Documentation

Link : https://pypi.python.org/pypi/engfmt/1.1.0

engfmt – It is a package used to read and write numbers in engineering format.

In engineering format a number generally includes the units if available and uses SI scale factors to indicate the magnitude of the number.

For example:



This package is designed to convert quantities between the various ways in which they are represented. Those ways are:

As a tuple:

For Eg: “1ns” – would be represented as (1e-9, ‘s’).

As a string in conventional formats:

For Eg: “1ns” – would be represented as ‘1e-9 s’ or as ‘0.000000001s’.

– This form is difficult to read for people.

– engfmt treats it more as a format meant for machines rather than people.

As a string in engineering format:

For Eg: “1ns” – would be represented as ‘1ns’.

– This form is difficult to read for machines

– engfmt treats it more as a human readable format.

The Quantity class is provided for converting between these various forms.

  • A quantity is the pairing of a real number and units, though the units may be empty.

1.It takes one or two arguments.

Eg: Quantity(1e-9) or Quantity(1e-9, ‘s’)

  • The first is taken to be the value, and the second, if given, is taken to be the units.
  • The value may be given as a float or as a string.
  • The string may be in floating point notation, in scientific notation, or in engineering format and may include the units.

Some examples of the conversions are given below:

For example, any of the following ways can be used to specify 1ns:

As a tuple:

>>> from engfmt import Quantity

>>> period = Quantity(1e-9, ‘s’)

>>> print(period)


As a string in conventional formats:

>>> period = Quantity(‘0.000000001 s’)

>>> print(period)


>>> period = Quantity(‘1e-9s’)

>>> print(period)


As a string in engineering format:

>>> period = Quantity(‘1ns’)

>>> print(period)


Note: In all cases, the giving the units is optional.

Conversions – Using quantity object you are able to convert it to any representations:

>>> h_line = Quantity(‘1420.405751786 MHz’)

# to converting to tuple with units

>>> h_line.to_tuple()

       (1420405751.786, ‘Hz’)

# to converting to string with engineering format

>>> h_line.to_eng()


# to converting to string with conventional format

>>> h_line.to_str()


You can also access the value without the units:

# convertig to float

>>> h_line.to_float()


# converting to a string with conventional format – without units

>>> h_line.to_unitless_eng()


# converting to string with engineering format – without units

>>> h_line.to_unitless_str()


# Get the units only

>>> h_line.units


There are many other functions also in this package, which is available in the link given.

Some of the functions are given below:

  • Quantities As Reals – You can use a quantity in the same way that you can use a real number, meaning that you can use it in expressions and it will evaluate to its real value.

For Example:

     >>> period = Quantity(‘1us’)

     >> print(period) 


  • Quantity Class – Quantity class can be used directly, like shortcut functions.

      For Example:

      >>> from engfmt import Quantity

      >>> h_line = Quantity(‘1420.405751786 MHz’)

      >>> str(h_line)


      >>> float(h_line)


  • Physical Constants – The Quantity class also supports a some physical constants.

      For Example:

     Plank’s constant:

      >>> plank = Quantity(‘h’)

      >>> print(plank)


  • Exceptions:

The best thing in this is it also gives Exceptions:

Eg: A ValueError is raised if engfmt cannot convert a string it into a number:

For Example:
			>>> try:
			...     value, units = quant_to_tuple('xxx')
			... except ValueError as err:
			...     print(err)
			xxx: not a valid number.

Installation / Usage :

Requires Python2.7 or Python3.3 or better.

1. Use ‘pip install engfmt’ in the cmd prompt to install.

2. By importing the .py file:

  • Download the package from the link.
  • Copy the engfmt.py from the package and put in the working directory of the python.
  • Import the file by from engfmt import* / from engfmt import Quantity.

Story of minus into minus is plus & programming for the same

Children from 8th were learning algebra and had difficulties with the sign operations. They were able to come up with stories of multiplying minus into plus, plus into minus and plus into plus but they couldn’t come up with a story of minus into minus. They asked the volunteers and facilitators to tell a story for it but they couldn’t get the right story for it. Sanjeev gave a story and explained how negative value multiplied with negative value becomes positive. Children even tried the story on the staircase. They closed their eyes and walked backward (negative) and facing down the staircase (negative) and when they opened their eyes they saw themselves climbed few steps up(Positive). They were excited and were able to implement it on their algebraic equations. They had fun while learning it.

Goanimate story:

Scratch program that randomly takes two numbers and does the same story.

link to scratch code: https://scratch.mit.edu/projects/296602417/


How to compress image size in Ubuntu

1. Open the terminal (Ctrl + Alt + T).

2. Install imagemagick by

sudo apt-get install imagemagick

2. Go to the directory of the folder in which you want to reduce the image size.

3. Then type the following command

mogrify -resize 800x * 

Example :

dell@Inspiron:~/Desktop/Image/$ mogrify -resize 800x *

Inauguration of clay room


The Roof was built with slabs that were attached together with bindings, and sealed off with some material that had become torn and corroded. Thus making rain water seep in. The solution was covering the cracks with tar sheets. Naveen had got the excess sheets from the repair works at Aura Auro Design’s Lab. He also got a Flame thrower that was antique 😉 (We along with the children had a time figuring out how to light it up) It was a manual tool we had to compress air and it would send out a mixture of kerosene and air that would burn. eventually 🙂 . The children started to measure and cut out the tar sheets from a roll. Naveen  and the children placed the sheets and heated them to stick on the roof with the flame thrower.

We hope this will prevent rain water from seeping in. The roof was then painted with a bright yellow oil paint. We bought 6 liters of oil paint. Children started painting during their sleepover. It took two evenings to paint 2 coat of painting on the roof.

Painting Inside:



The room was now ready to be inaugurated on Sri Aurobindo’s birthday. We had as our chief guest, Swami Sarvasahananda from Ramakrishna Mission, Chengalpattu. He graced our space with his blessings, talk and music. That morning the school was abuzz with activity. Children had stayed over the previous night to participate in the dawnfire meditation. When we came from there, we were working on decorating the clay room. Garlands were made, photos of Sri Aurobindo, Mother, Sri Ramakrishna, Sarada Devi and Swami Vivekananda were decorated. Lamps were kept ready for the opening. Children with help from their teachers got the PA system ready. The harmonium and tabla were arranged. Gopal from Mantra pottery joined us that morning to do clay work. It was a session that children and adults enjoyed. The Swamiji lit the lamp and invited the teachers to do the same. Once the lamps were lit, we all connected with the Divine Mother through songs that the Swamiji and children sang. For those who could remember how forlorn the room had been, it was touching to see how the same little room was shining with all of us invoking the Divine.

As one of the facilitators in creating our clay room, I witnessed the transformation of a space we had neglected over the years into a bright space that we look at every day. That we can transform our environment with one-pointed concentration, team-work, openness to learn, consecration of our work to the Divine are learnings that will stay with us and reveal themselves to us as and when we are ready to understand them.

When I was working with the children in the clay room I learnt to be patient. Involved all the children and gave equal opportunities to all the children. Learnt team work from the children. I saw sharing and caring from the children while working as a team for my self and for others.

(x + y + z)^3 Visualisation

Naveen and I were trying to visualise (x + y + z)^3 with Lavanya a 9th grader in Udavi using the Montessori Cube.

We are able to formulate (x + y + z)^3 = x^3 + y^3 +z^3 + 3x^2y + 3x^2z + 3y^2x + 3y^2z + 3z^2x + 3z^2y + 6xyz

Bala & Naveen

Quadcopter Quadcopter

In STEM Land 9th std children were very eager to do the Quad copter. They wanted to do something different which inspires themselves as well others. We are building an i-smart class room and the 9th std children wanted to paint the room themselves so they stayed the night at the school and painted the room. After the painting they saw a Movie called October sky. By seeing the Movie children got inspired and first thought of building a rocket, but then settled down to build the quadcopter. They felt that since they are in 9th std and would be busy next year with the board examinations they should make full use of STEM Land this year and do something interesting. They thought of it and came up with an idea of making a Quadcopter. They started researching online and looking at videos and worked out the parts they needed to build a quadcopter.They took a DVD and carefully cut it with equal sides and placed the RF control receiver board, four motors and their propellers on it and soldered them. Children used the Big shot camera battery from STEM Land and connected it to the receiver. While connecting the battery and the receiver a pin broke.They traced the pins and soldered connectors and fixed the problem. They figured out to connect the transmitter with the receiver by keeping the transmitter and the receiver so close to each other and pressed the button and waited for few seconds and connected it. They were so happy and eager to finish it and were working on it even during their break. They have almost completed assembling the Quadcopter and now they are working on it to make it fly. Currently it hovers a few cm from the ground before loosing contact with the transmitter. The 8th and 7th children were also looking at it enthusiastically and enjoyed.

Clay room

Painting Outside:

Third graders took responsibility to paint outside. This being a room for clay and woodwork, we wanted to paint it with a natural brownish red-soil color. We inquired with a few painters and once they understood our idea, they all suggested extracting the color from red-soil and binding it with Fevicol. Children in 5,6 and 7 stay over in school on Wednesdays. One Thursday morning, we went with pands and mumpties and collected red soil.

Once the soil was on hand, the third graders sieved it. Water was added to the soil and mixed well. This had to be filtered to extract the color. For the filter, we used some of the cloth bags we receive in grocery stores that don’t use plastic any more. We tool 4 liters of the red-soil water and mixed it with 2 liter of Fevicol. Fevicol made the paint thick. We painted the wall and as it dried up, the wall looked beautiful with hues of orange, red and yellow. We wanted a darker shade since we planned to paint patterns on the wall inspired by Warli art. So for the next coat, we added some brown water color that was on hand. A lovely dark shade was the result. The room is hexagonal giving us six panels to paint on. Over a few evenings after school, teachers and students painted patterns on the wall. We have a panel with a tree and a deer on a full moon night. One more with the Matrimandir, Banyan tree and children visiting there. Some of the paintings did not come well and we painted over them to create a fresh new wall to paint over.

Wooden Torch in Isai STEM land

In Isai Ambalam school children waned to make different types of lights to use it during sleep over. It took 2 to 3 weeks  to build a nice wooden torch. So they started cutting the bamboo during STEM land period. Once they cut the bamboo they  started to build the circuit on a bread board and then started soldering  with wires. Then they made hole in the bamboo with a drill to fix a switch. Then for the front part they really wanted to use some cone shape and to fix the LED. At first they use a waste water bottle. They cut the bottle and took the cone shape but it didn’t last for long time. It also didn’t look good. Then they were struggling with chart paper to make a head for the torch. Then students got some ideas like that what all can be made with bamboo. Some wanted to build a study lamp. These things were made  4th and 5th grades. Three girls thought it is very difficult to build a torch. When some students started to build a study lamp these girls got inspired and they also started to build a torch. When they finish making the torch Monica came to visit STEM land they presented this torch to her. Monica gave a beautiful words for those kids. I also added a image with the words from Monica.