In [1]:

    

print("Hello Sir Newton.")


    

    




Hello Sir Newton.

In [2]:

    

print("Hey Isaac, what's Newton?!")
print("How is it going, Gottfried?")


    

    




Hey Isaac, what's Newton?!
How is it going, Gottfried?

In [3]:

    

h_bar = 1.05457e-34


    

In [4]:

    

2plus_forty = 42  # bad


    

    




  File "<ipython-input-4-4ce07ef7122d>", line 1
    2plus_forty = 42  # bad
              ^
SyntaxError: invalid syntax

In [5]:

    

two_plus40 = 42   # good


    

In [6]:

    

pi = 3.14159
h = 2 * pi * h_bar
print(h)


    

    




6.6260531326e-34

In [7]:

    

dims = 3                   # int, only digits
ndim = 3.0                 # float, because of the '.'
h_bar = 1.05457e-34        # float, because of the '.' or 'e'
label = "Energy (in MeV)"  # str, quotes surround the text


    

In [8]:

    

type(h_bar)


    

    
Out[8]:





float

In [9]:

    

type(42)


    

    
Out[9]:





int

In [10]:

    

float(42)


    

    
Out[10]:





42.0

In [11]:

    

int("28")


    

    
Out[11]:





28

In [12]:

    

int("quark")


    

    




---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-12-df7f23f9b45e> in <module>()
----> 1 int("quark")

ValueError: invalid literal for int() with base 10: 'quark'

In [13]:

    

x = 3
x = 1.05457e-34
x = "Energy (in MeV)"


    

In [14]:

    

bool(0)


    

    
Out[14]:





False

In [15]:

    

bool("Do we need Oxygen?")


    

    
Out[15]:





True

In [16]:

    

"Gorgus" / 2.718


    

    




---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-16-8cdca6dc67bb> in <module>()
----> 1 "Gorgus" / 2.718

TypeError: unsupported operand type(s) for /: 'str' and 'float'

In [17]:

    

x = 1  # Create x
del x  # Destroy x


    

In [18]:

    

x = (42 * 65) - 1


    

In [19]:

    

42 + 65


    

    
Out[19]:





107

In [20]:

    

(42 + 65) + 1


    

    
Out[20]:





108

In [21]:

    

x = "Nature abhors a vacuum"
y = 'but loves a mop!'


    

In [22]:

    

p = "proton"


    

In [23]:

    

p[1]


    

    
Out[23]:





'r'

In [24]:

    

p[-1]


    

    
Out[24]:





'n'

In [25]:

    

p[len(p)-2]  # also works, but why write len(p) all the time?


    

    
Out[25]:





'o'

In [26]:

    

p[2:5]


    

    
Out[26]:





'oto'

In [27]:

    

p[1:-1]


    

    
Out[27]:





'roto'

In [28]:

    

p[-1:2]


    

    
Out[28]:





''

In [29]:

    

q = "AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz"


    

In [30]:

    

q[2:-2:2]


    

    
Out[30]:





'BCDEFGHIJKLMNOPQRSTUVWXY'

In [31]:

    

q[1::2]


    

    
Out[31]:





'abcdefghijklmnopqrstuvwxyz'

In [32]:

    

q[::-3]


    

    
Out[32]:





'zYwVtSqPnMkJhGeDbA'

In [33]:

    

x = "neveroddoreven"
x == x[::-1]


    

    
Out[33]:





True

In [34]:

    

my_slice = slice(3, 1415, 9)  # my slice of the pi
x[my_slice]


    

    
Out[34]:





'ee'

In [35]:

    

"kilo" + "meter"


    

    
Out[35]:





'kilometer'

In [36]:

    

"x^" + str(2)


    

    
Out[36]:





'x^2'

In [37]:

    

"newto" * 10


    

    
Out[37]:





'newtonewtonewtonewtonewtonewtonewtonewtonewtonewto'

In [38]:

    

"H + H"    " -> H2"


    

    
Out[38]:





'H + H -> H2'

In [39]:

    

quote = ("Science is what we understand well enough to explain to a computer. "
         "Art is everything else we do. "
         "-Donald Knuth")


    

In [40]:

    

x = "It's easy!"
y = 'The computer said, "Does not compute."'


    

In [41]:

    

"Bones said, \"He\'s dead, Jim.\""


    

    
Out[41]:





'Bones said, "He\'s dead, Jim."'

In [42]:

    

"""Humpty, he sat on a wall,
Then Humpty, he had a great fall.
But all the king's horses
And men with their forces
Couldn't render his entropy small.
"""


    

    
Out[42]:





"Humpty, he sat on a wall,\nThen Humpty, he had a great fall.\nBut all the king's horses\nAnd men with their forces\nCouldn't render his entropy small.\n"

In [43]:

    

header = "  temperature  pressure\t value \n"


    

In [44]:

    

header.strip()


    

    
Out[44]:





'temperature  pressure\t value'

In [45]:

    

header.upper()


    

    
Out[45]:





'  TEMPERATURE  PRESSURE\t VALUE \n'

In [46]:

    

"10".isdigit()


    

    
Out[46]:





True

In [47]:

    

"10.10".isdigit()


    

    
Out[47]:





False

In [48]:

    

"{0} gets into work & then his {1} begins!".format("Hilbert", "commute")


    

    
Out[48]:





'Hilbert gets into work & then his commute begins!'

In [49]:

    

x = 42
y = 65.0


    

In [50]:

    

"x={0} y={1}".format(x, y)


    

    
Out[50]:





'x=42 y=65.0'

In [51]:

    

"x=" + str(x) + " y=" + str(y)


    

    
Out[51]:





'x=42 y=65.0'

In [52]:

    

import constants

two_pi = 2 * constants.pi
h_bar = constants.h / two_pi


    

In [53]:

    

from constants import pi, h

two_pi = 2 * pi
h_bar = h / two_pi


    

In [54]:

    

import constants as c

constants = 2.71828

two_pi = 2 * c.pi
h_bar = c.h / 2 / c.pi


    

In [55]:

    

from constants import pi as PI, h as H

two_pi = 2 * PI
h_bar = H / two_pi