x_int = 20 #this is an integer
x_float = 20.0 #this is a floating point number

x = 5
y = 3
z = x/y
print z

z = 10/3.
print z

from __future__ import division

print 5/2

string1 = 'datatypes'
string2 = "Don't stop believin'"
print string1
print string2

print string1[0] #first character
print string1[0:2] #first two characters
print string1[2:len(string1)] #everything after second character
print string1[2:5]
print string1[-2:] #last two characters
print string1[0:len(string1)]
print string1[:]

def my_function():
    """ This a simple function to demonstrate
    the use of triple quotes. You would normally
    put some a brief description of your function in this space."""
    pass #Tells interpreter: nothing to see here, carry on.

a = 'asasa'
#a[2] = 'd' #throws error

num_list = [2, 3, 210, 4]
str_list = ['a', 'sdff', 'asd']
rand_list = [[12, 10], 'a', 1, [10, 'x', 12]]

print "num_list: %s" %num_list
print "str_list: %s" %str_list
print "rand_list: %s" %rand_list

print rand_list[0][1]

#generate a list that contains the square of each number in num_list:
num_list_sq = [num**2 for num in num_list ]
print num_list_sq

#generate a list that contains the square of each number in num_list
#if the number is exactly divisible by 3
num_list_sq2 = [num**2 if num%3==0 else num for num in num_list ]
print num_list_sq2

num_list_sq3 = []
for num in num_list:
    if num%3==0:
        num_list_sq3.append(num**2)
    else: 
        num_list_sq3.append(num)

print num_list_sq3

yr_strs = ('year1', 'year2', 'year3')
yr_nums = 2009, 2010, 2011
tupl = ('a',)

tup_num = tuple(num_list)
print yr_nums
print tup_num

print "%s: %s" %(yr_strs[0], yr_nums[1])

contacts = {'John': 6462100, 'Adam': 6461870}

print contacts

mooring1 = {'Date': '2010-09-13', 'Lat': 10.1,'Lon': 78.5, 'salinity': [28.8, 31.3, 34.5, 35.1]}
print mooring1['Lon']

dict_ex = dict(zip(['a','b', 'c', 'd', 'e'], range(5)))
print dict_ex

print dict_ex.keys()
print dict_ex.values()

dict_ex['a']

import numpy as np

x = np.array([12, 10, 3])
print x

a = np.arange(5,10,0.5) #note: endpoint is excluded
print a

print np.linspace(0,20,6) #note: endpoint is included

b = np.zeros((3,3))
print b

ones3d = np.ones((2,5,2))
print ones3d

rand_array = np.random.randint(3,10, (4,5))
print rand_array
print rand_array.shape

a = np.arange(10)
b = np.ones((10,1))
print a*b.T

x = np.arange(10)
print x
x_ma = np.ma.masked_where(x>5, x)
print x_ma
print x_ma.mask

x_ma_mean = np.mean(x_ma)
print x_ma_mean

y = np.array([1, 2, 3, np.nan, 5])
print np.mean(y)
print np.nanmean(y)

y_ma = np.ma.masked_where(np.isnan(y), y, copy=True)
y_ma2 = np.ma.masked_invalid(y)
print y_ma.mean()
y[2] = 10 #if copy is set to False, then this modifies y_ma as well
print y
print y_ma


dtype_list1 = [('x','f4'), ('y','f4'), ('z','f4')]
coords = np.zeros((5,1), dtype=dtype_list1)
print coords

dtype_list2 = [('temp','f4'), ('sal','f4'), ('lon','f4'), ('lat','f4')]
gridded_data = np.zeros((4,5), dtype=dtype_list2)
print gridded_data

gridded_data['temp'] = np.random.randint(20,30,(4,5))
gridded_data['sal'] = np.random.randint(30,35,(4,5))
lon = np.linspace(0,20,4)
lat = np.linspace(10,30,5)
lon,lat = np.meshgrid(lat,lon)
gridded_data['lon'] = np.round(lon) 
gridded_data['lat'] = np.round(lat)
print gridded_data

print gridded_data['sal'] 

print gridded_data['lon']

print gridded_data[['temp', 'lat']]

gridded_data.shape

np.mean(gridded_data['temp'], axis=0)