In [1]:

    

"Hello World!"


    

    
Out[1]:





'Hello World!'

In [2]:

    

lista = ["Raul", "Ezequiel"]


    

In [5]:

    

for name in lista:
    print("hello ", name)


    

    




hello  Raul
hello  Ezequiel

In [1]:

    

class Switcher(object):
    def numbers_to_methods_to_strings(self, argument):
        """Dispatch method"""
        # prefix the method_name with 'number_' because method names
        # cannot begin with an integer.
        method_name = 'number_' + str(argument)
        # Get the method from 'self'. Default to a lambda.
        method = getattr(self, method_name, lambda: "nothing")
        # Call the method as we return it
        return method()

    def number_0(self):
        return "zero"

    def number_1(self):
        return "one"

    def number_2(self):
        return "two"


    

In [2]:

    

switcher = Switcher()


    

In [7]:

    

switcher.numbers_to_methods_to_strings(0)


    

    
Out[7]:





'zero'

In [1]:

    

import numpy as np


    

In [2]:

    

neurons = np.random.random((10, 5))


    

In [3]:

    

patr = np.random.random((1, 5))


    

In [4]:

    

distances = np.linalg.norm(neurons - patr, axis=1)


    

In [5]:

    

closest = distances.argmin()


    

In [2]:

    

from sympy import *


    

In [4]:

    

init_printing()


    

In [5]:

    

x, y, z = symbols('x y z')
Integral(sqrt(1/x), x)


    

    
Out[5]:





$$\int \sqrt{\frac{1}{x}}\, dx$$

In [12]:

    

expr =  x**3 + 3*x**2*y + 3*x*y**2 + y**3
expr


    

    
Out[12]:





$$x^{3} + 3 x^{2} y + 3 x y^{2} + y^{3}$$

In [15]:

    

factors = factor(expr)
factors


    

    
Out[15]:





$$\left(x + y\right)^{3}$$

In [16]:

    

expand(factors)


    

    
Out[16]:





$$x^{3} + 3 x^{2} y + 3 x y^{2} + y^{3}$$

In [22]:

    

derivada = Derivative(expr, x)
derivada


    

    
Out[22]:





$$\frac{\partial}{\partial x}\left(x^{3} + 3 x^{2} y + 3 x y^{2} + y^{3}\right)$$

In [23]:

    

derivada.doit()


    

    
Out[23]:





$$3 x^{2} + 6 x y + 3 y^{2}$$

In [27]:

    

integral = Integral(derivada.doit(), x)
integral


    

    
Out[27]:





$$\int 3 x^{2} + 6 x y + 3 y^{2}\, dx$$

In [28]:

    

integral.doit()


    

    
Out[28]:





$$x^{3} + 3 x^{2} y + 3 x y^{2}$$

In [29]:

    

x = Symbol('x')
Limit(1/x, x, S.Infinity)


    

    
Out[29]:





$$\lim_{x \to \infty} \frac{1}{x}$$

In [30]:

    

Limit(1/x, x, S.Infinity).doit()


    

    
Out[30]:





$$0$$

In [32]:

    

Limit(1/x, x, 0, dir='-')


    

    
Out[32]:





$$\lim_{x \to 0^-} \frac{1}{x}$$

In [1]:

    

for x in range(41, 51):
    print('%d == %02d%02d when x=%d' % (x ** 2, x - 25, (50 - x) ** 2, x))


    

    




1681 == 1681 when x=41
1764 == 1764 when x=42
1849 == 1849 when x=43
1936 == 1936 when x=44
2025 == 2025 when x=45
2116 == 2116 when x=46
2209 == 2209 when x=47
2304 == 2304 when x=48
2401 == 2401 when x=49
2500 == 2500 when x=50

In [24]:

    

f = Function('f')
F = Function('F')
x, y, u= symbols('x y u')


    

In [5]:

    

eq = -2*f(x,y).diff(x) + 4*f(x,y).diff(y) + 5*f(x,y) - exp(x + 3*y)
eq


    

    
Out[5]:





$$5 f{\left (x,y \right )} - e^{x + 3 y} - 2 \frac{\partial}{\partial x} f{\left (x,y \right )} + 4 \frac{\partial}{\partial y} f{\left (x,y \right )}$$

In [6]:

    

pdsolve(eq)


    

    
Out[6]:





$$f{\left (x,y \right )} = \left(F{\left (4 x + 2 y \right )} + \frac{1}{15} e^{\frac{x}{2} + 4 y}\right) e^{\frac{x}{2} - y}$$

In [7]:

    

classify_pde(eq)


    

    
Out[7]:





('1st_linear_constant_coeff', '1st_linear_constant_coeff_Integral')

In [37]:

    

u = f(x, y)
ux = u.diff(x)
uy = u.diff(y)
eq = exp(2*x)*(u.diff(y)) + y*u - u
eq


    

    
Out[37]:





$$y f{\left (x,y \right )} - f{\left (x,y \right )} + e^{2 x} \frac{\partial}{\partial y} f{\left (x,y \right )}$$

In [15]:

    

sol = pdsolve(eq)
sol


    

    
Out[15]:





$$f{\left (x,y \right )} = e^{\frac{1}{2} \left(- y^{2} + 2 y + 2 F{\left (x \right )}\right) e^{- 2 x}}$$

In [16]:

    

eq = Eq(1 + (2*(ux/u)) + (3*(uy/u)))
eq


    

    
Out[16]:





$$1 + \frac{2 \frac{\partial}{\partial x} f{\left (x,y \right )}}{f{\left (x,y \right )}} + \frac{3 \frac{\partial}{\partial y} f{\left (x,y \right )}}{f{\left (x,y \right )}} = 0$$

In [18]:

    

sol = pdsolve(eq)
sol


    

    
Out[18]:





$$f{\left (x,y \right )} = F{\left (3 x - 2 y \right )} e^{- \frac{2 x}{13} - \frac{3 y}{13}}$$

In [20]:

    

eq = (3*x - 2*y)*exp(-2*x/13 - 3*y/13)
eq


    

    
Out[20]:





$$\left(3 x - 2 y\right) e^{- \frac{2 x}{13} - \frac{3 y}{13}}$$

In [21]:

    

eq = x*(u.diff(x)) - y*(u.diff(y)) + y**2*u - y**2
eq


    

    
Out[21]:





$$x \frac{\partial}{\partial x} f{\left (x,y \right )} + y^{2} f{\left (x,y \right )} - y^{2} - y \frac{\partial}{\partial y} f{\left (x,y \right )}$$

In [34]:

    

sol = pdsolve(eq)
sol


    

    
Out[34]:





$$f{\left (x,y \right )} = F{\left (x y \right )} e^{\frac{y^{2}}{2}} + 1$$

In [32]:

    

Eq(f(x, y), F(x*y)*exp(y**2/2) + 1)


    

    
Out[32]:





$$f{\left (x,y \right )} = F{\left (x y \right )} e^{\frac{y^{2}}{2}} + 1$$

In [35]:

    

sol ==  Eq(f(x, y), F(x*y)*exp(y**2/2) + 1)


    

    
Out[35]:





True

In [38]:

    

eq = y*x**2*u + y*u.diff(x) + u.diff(y)
eq


    

    
Out[38]:





$$x^{2} y f{\left (x,y \right )} + y \frac{\partial}{\partial x} f{\left (x,y \right )} + \frac{\partial}{\partial y} f{\left (x,y \right )}$$

In [40]:

    

sol = pdsolve(eq)
sol


    

    
Out[40]:





$$f{\left (x,y \right )} = F{\left (- 2 x + y^{2} \right )} e^{- \frac{x^{3}}{3}}$$

In [41]:

    

Eq(f(x, y), F(-2*x + y**2)*exp(-x**3/3))


    

    
Out[41]:





$$f{\left (x,y \right )} = F{\left (- 2 x + y^{2} \right )} e^{- \frac{x^{3}}{3}}$$

In [43]:

    

f = -2*x + y**2
diff(f, y)


    

    
Out[43]:





$$2 y$$

In [ ]: