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Python - Map

 

 

NOTE 1 : All the examples in this page are written in Python 3.x. It may not work if you use Pyton 2.x

NOTE 2 : All the examples in this page are assumed to be written/run on Windows 7 unless specifically mentioned. You MAY (or may not) need to modify the syntax a little bit if you are running on other operating system.

  • Applying a map with normal function with one argument  - Example 1
  • Applying a map with lambda function with one argument - Example 2
  • Applying a map with normal function with multiple argument  - Example 3
  • Applying a map with lambda function with multiple argument - Example 4
  • Printing out all the items in a Mapped Object - Example 5
  • Printing out all the items in a Mapped Object - Example 6
  • Printing out all the items in a Mapped Object - Example 7
  • Indexing items in a Mapped Object - Example 8

 

 

Examples :

 

< Example 1 >

 

def f(x):

    y = x^2 + 2*x + 3

    return y

 

xList = [-3,-2,-1,0,1,2,3]

 

yList = map(f,xList)

print(yList)

print(list(yList))

 

Result :----------------------------------

<map object at 0x0306C770>

[2, -1, -4, 5, 6, 11, 8]

 

 

< Example 2 >

 

xList = [-3,-2,-1,0,1,2,3]

 

yList = map(lambda x: x^2 + 2*x + 3,xList)

print(yList)

print(list(yList))

 

Result :----------------------------------

<map object at 0x0314C7D0>

[2, -1, -4, 5, 6, 11, 8]

 

 

< Example 3 >

 

def timeStamp(y,m,d):

    tStamp = str(y) + "-" + m + "-" + str(d)

    return tStamp

 

yList = [2017,2017,2017,2017]

mList = ["Jan","Feb","Mar","Apr"]

dList = [1,3,6,7];

 

tStamp = map(timeStamp,yList,mList,dList)

print(tStamp)

print(list(tStamp))

 

Result :----------------------------------

<map object at 0x03000A30>

['2017-Jan-1', '2017-Feb-3', '2017-Mar-6', '2017-Apr-7']

 

 

< Example 4 >

 

yList = [2017,2017,2017,2017]

mList = ["Jan","Feb","Mar","Apr"]

dList = [1,3,6,7];

 

tStamp = map(lambda y,m,d : str(y) + "-" + m + "-" + str(d) ,yList,mList,dList)

print(tStamp)

print(list(tStamp))

 

Result :----------------------------------

<map object at 0x03091A30>

['2017-Jan-1', '2017-Feb-3', '2017-Mar-6', '2017-Apr-7']

 

 

< Example 5 >

 

yList = [2017,2017,2017,2017]

mList = ["Jan","Feb","Mar","Apr"]

dList = [1,3,6,7];

 

tStamp = map(lambda y,m,d : str(y) + "-" + m + "-" + str(d) ,yList,mList,dList)

 

for index, item in enumerate(tStamp):

   print(index,',',item)

    

 

Result :----------------------------------

0 , 2017-Jan-1

1 , 2017-Feb-3

2 , 2017-Mar-6

3 , 2017-Apr-7

 

 

< Example 6 >

 

yList = [2017,2017,2017,2017]

mList = ["Jan","Feb","Mar","Apr"]

dList = [1,3,6,7];

 

tStamp = map(lambda y,m,d : str(y) + "-" + m + "-" + str(d) ,yList,mList,dList)

 

for item in enumerate(tStamp):

   print(item)

 

 

Result :----------------------------------

(0, '2017-Jan-1')

(1, '2017-Feb-3')

(2, '2017-Mar-6')

(3, '2017-Apr-7')

 

 

< Example 7 >

 

yList = [2017,2017,2017,2017]

mList = ["Jan","Feb","Mar","Apr"]

dList = [1,3,6,7];

 

tStamp = map(lambda y,m,d : str(y) + "-" + m + "-" + str(d) ,yList,mList,dList)

 

for item in enumerate(tStamp):

    print(item[0],',',item[1])

 

 

Result :----------------------------------

0 , 2017-Jan-1

1 , 2017-Feb-3

2 , 2017-Mar-6

3 , 2017-Apr-7

 

 

< Example 8 >

 

yList = [2017,2017,2017,2017]

mList = ["Jan","Feb","Mar","Apr"]

dList = [1,3,6,7];

 

tStamp = map(lambda y,m,d : str(y) + "-" + m + "-" + str(d) ,yList,mList,dList)

 

tStampList = list(tStamp);

 

print(tStampList)

print(tStampList[0])

print(tStampList[1:3])

 

 

Result :----------------------------------

['2017-Jan-1', '2017-Feb-3', '2017-Mar-6', '2017-Apr-7']

2017-Jan-1

['2017-Feb-3', '2017-Mar-6']

 

 

< Example xx >