In [1]:

    

cd "/home/bakuda/pandas-book/ch02/"


    

    




/home/bakuda/pandas-book/ch02

In [2]:

    

ls


    

    




movielens/  names/  usagov_bitly_data2012-03-16-1331923249.txt

In [3]:

    

a = "this is a string"


    

In [7]:

    

#String and tuple are immutable
b =a.replace("string", "long string")
print a
print b


    

    




this is a string
this is a long string

In [8]:

    

x=5.6
str(x)


    

    
Out[8]:





'5.6'

In [10]:

    

s ='python'
list(s)


    

    
Out[10]:





['p', 'y', 't', 'h', 'o', 'n']

In [11]:

    

s


    

    
Out[11]:





'python'

In [12]:

    

s+str(x)


    

    
Out[12]:





'python5.6'

In [15]:

    

template = "%2.2f %s are worth $%d"


    

In [16]:

    

template % (60.5, "INR", 1)


    

    
Out[16]:





'60.50 INR are worth $1'

In [17]:

    

True and False


    

    
Out[17]:





False

In [18]:

    

a = range(1,5)


    

In [19]:

    

a


    

    
Out[19]:





[1, 2, 3, 4]

In [20]:

    

type(a)


    

    
Out[20]:





list

In [21]:

    

for i in a:
    if i:
        print "%d is True" %(i)


    

    




1 is True
2 is True
3 is True
4 is True

In [22]:

    

b =[]
if b:
    print "b is not empty"
else:
    print "b is empty"


    

    




b is empty

In [25]:

    

[bool(i) for i in a]


    

    
Out[25]:





[True, True, True, True]

In [26]:

    

s = '3.1412'
type(s)


    

    
Out[26]:





str

In [29]:

    

fs = float(s)
float(s)


    

    
Out[29]:





3.1412

In [30]:

    

int(fs)


    

    
Out[30]:





3

In [31]:

    

bool(fs)


    

    
Out[31]:





True

In [32]:

    

from datetime import datetime, date, time


    

In [33]:

    

dt = datetime(2011, 10, 29, 20, 30, 21)


    

In [37]:

    

dt.day


    

    
Out[37]:





29

In [38]:

    

dt.hour


    

    
Out[38]:





20

In [39]:

    

dt.second


    

    
Out[39]:





21

In [40]:

    

range(0,20,3)


    

    
Out[40]:





[0, 3, 6, 9, 12, 15, 18]

In [41]:

    

xrange(0,20,3)


    

    
Out[41]:





xrange(0, 21, 3)

In [42]:

    

for i in range(0,10,1):
    print i*i


    

    




0
1
4
9
16
25
36
49
64
81

In [44]:

    

for i  in xrange(10):
    print i*i


    

    




0
1
4
9
16
25
36
49
64
81

In [47]:

    

count=0
for x in xrange(100):
    if x%3==0 and x%5==0:
        count +=1
        print x


    

    




0
15
30
45
60
75
90

In [48]:

    

count


    

    
Out[48]:





7

In [51]:

    

t=tuple(xrange(10))


    

In [52]:

    

type(t)


    

    
Out[52]:





tuple

In [53]:

    

t


    

    
Out[53]:





(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)

In [54]:

    

t[0]


    

    
Out[54]:





0

In [55]:

    

t.append(xrange(20,25,1))


    

    




---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-55-075fd3536ac6> in <module>()
----> 1 t.append(xrange(20,25,1))

AttributeError: 'tuple' object has no attribute 'append'

In [56]:

    

a=xrange(10)
b=xrange(20,30,1)
c=xrange(40,50,1)


    

In [59]:

    

seq = [a,b,c]
#for i,j,k in [a,b,c]:
#    print i*j*k


    

In [60]:

    

seq


    

    
Out[60]:





[xrange(10), xrange(20, 30), xrange(40, 50)]

In [64]:

    

print list(a)
print list(b)
print list(c)


    

    




[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
[40, 41, 42, 43, 44, 45, 46, 47, 48, 49]

In [70]:

    

l= list(a)
l.append(11)


    

In [71]:

    

l


    

    
Out[71]:





[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11]

In [72]:

    

11 in l


    

    
Out[72]:





True

In [73]:

    

list(a) + list(b)


    

    
Out[73]:





[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]

In [75]:

    

d =list(a).extend(list(c))


    

In [78]:

    

type(d)


    

    
Out[78]:





NoneType

In [79]:

    

t = list(a)


    

In [80]:

    

t


    

    
Out[80]:





[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

In [81]:

    

[p*p-2 for p in t]


    

    
Out[81]:





[-2, -1, 2, 7, 14, 23, 34, 47, 62, 79]

In [87]:

    

t.sort()
t


    

    
Out[87]:





[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

In [84]:

    

w=[4,1,2,9,20,10]


    

In [85]:

    

w.sort()


    

In [86]:

    

w


    

    
Out[86]:





[1, 2, 4, 9, 10, 20]

In [91]:

    

b=['he','a', 'hello','howdy','thereis','she','neighbour']


    

In [92]:

    

b.sort(key=len)


    

In [93]:

    

b


    

    
Out[93]:





['a', 'he', 'she', 'hello', 'howdy', 'thereis', 'neighbour']

In [94]:

    

w


    

    
Out[94]:





[1, 2, 4, 9, 10, 20]

In [95]:

    

w[1:5]


    

    
Out[95]:





[2, 4, 9, 10]

In [99]:

    

w[-2:]


    

    
Out[99]:





[10, 20]

In [100]:

    

w[:-2]


    

    
Out[100]:





[1, 2, 4, 9]

In [101]:

    

w[:4]


    

    
Out[101]:





[1, 2, 4, 9]

In [102]:

    

len(w)


    

    
Out[102]:





6

In [103]:

    

w[6:8]=[11,22,22]


    

In [104]:

    

w


    

    
Out[104]:





[1, 2, 4, 9, 10, 20, 11, 22, 22]

In [105]:

    

w[-6:-2]


    

    
Out[105]:





[9, 10, 20, 11]

In [106]:

    

w[::2]


    

    
Out[106]:





[1, 4, 10, 11, 22]

In [107]:

    

w[::]


    

    
Out[107]:





[1, 2, 4, 9, 10, 20, 11, 22, 22]

In [109]:

    

w[::3]


    

    
Out[109]:





[1, 9, 11]

In [110]:

    

w[::-1]


    

    
Out[110]:





[22, 22, 11, 20, 10, 9, 4, 2, 1]

In [111]:

    

w


    

    
Out[111]:





[1, 2, 4, 9, 10, 20, 11, 22, 22]

In [113]:

    

for i,val in enumerate(w):
    print "%d th element is=%d" %(i,val)


    

    




0 th element is=1
1 th element is=2
2 th element is=4
3 th element is=9
4 th element is=10
5 th element is=20
6 th element is=11
7 th element is=22
8 th element is=22

In [120]:

    

some_list=['aaa','bar','zoo','aba']


    

In [121]:

    

dict((v,i*i) for i,v in enumerate(some_list))


    

    
Out[121]:





{'aaa': 0, 'aba': 9, 'bar': 1, 'zoo': 4}

In [122]:

    

new_list=['bb','tar','poo','bab']


    

In [123]:

    

zip(some_list, new_list)


    

    
Out[123]:





[('aaa', 'bb'), ('bar', 'tar'), ('zoo', 'poo'), ('aba', 'bab')]

In [124]:

    

empty_dict = {'a':11, 'b':22, 'c':33}


    

In [125]:

    

empty_dict


    

    
Out[125]:





{'a': 11, 'b': 22, 'c': 33}

In [127]:

    

empty_dict['a']


    

    
Out[127]:





11

In [128]:

    

empty_dict['z']=2626


    

In [129]:

    

empty_dict


    

    
Out[129]:





{'a': 11, 'b': 22, 'c': 33, 'z': 2626}

In [131]:

    

'b' in empty_dict


    

    
Out[131]:





True

In [132]:

    

empty_dict.keys()


    

    
Out[132]:





['a', 'c', 'b', 'z']

In [133]:

    

empty_dict.values()


    

    
Out[133]:





[11, 33, 22, 2626]

In [134]:

    

dict(zip(range(5), range(50,55,1)))


    

    
Out[134]:





{0: 50, 1: 51, 2: 52, 3: 53, 4: 54}

In [135]:

    

strings = ['a', 'as', 'bat', 'car', 'dove', 'python']


    

In [136]:

    

[x for x in strings if len(x)>2]


    

    
Out[136]:





['bat', 'car', 'dove', 'python']

In [139]:

    

[x.upper() for x in strings if x.startswith('b') or x.startswith('a')]


    

    
Out[139]:





['A', 'AS', 'BAT']

In [140]:

    

some_tuples = [(1, 2, 3), (4, 5, 6), (7, 8, 9)]


    

In [141]:

    

flattened = [x for tup in some_tuples for x in tup]


    

In [142]:

    

flattened


    

    
Out[142]:





[1, 2, 3, 4, 5, 6, 7, 8, 9]

In [143]:

    

[x for tup in some_tuples for x in tup]


    

    
Out[143]:





[1, 2, 3, 4, 5, 6, 7, 8, 9]

In [145]:

    

type(some_tuples[0])


    

    
Out[145]:





tuple

In [146]:

    

some_tuples[0][0]


    

    
Out[146]:





1

In [147]:

    

strings = ['foo', 'card', 'bar', 'aaaa', 'abab']


    

In [149]:

    

strings.sort(key=len)
strings


    

    
Out[149]:





['foo', 'bar', 'card', 'aaaa', 'abab']

In [150]:

    

strings.sort(key=lambda x: len(set(list(x))))
strings


    

    
Out[150]:





['aaaa', 'foo', 'abab', 'bar', 'card']

In [154]:

    

len(set(list('foo')))


    

    
Out[154]:





2

In [155]:

    

pwd


    

    
Out[155]:





u'/home/bakuda/pandas-book/ch02'

In [ ]: