Py Functions

Question 1

string function, how to break a longer string into smaller strings?

Answer 1

]] < long_string >.split( ‘ )

• • split
• • it will split the long_string by the split_char into
• • strings which the long_string was made up of
• • built-in string function

Question 2

how to remove unwanted characters from the beginning or end of a string?

Answer 2

]] < short_string >.strip( char_to_remove )

• • strip
• • strip away the char_remove from the beginning or
• • end of the short_string

Question 3

how can you find out if a value is part of a list or not? , a function also used in SQL
( provide a practical example )

Answer 3

]] < value > in < list_name >
]] True / False
– in
– query the list to get the response whether a value is included (True) or not (False)

Question 4

how to ask whether a value/string is numeric, or not?
what will it check?
what will the answer reveal?
which other function is closely related?

Answer 4

]] < string >.isnumeric( )

– it checks whether all characters in the value are numeric, incl expressions as power of etc.
– it should probably be considered as a check of chars and expression
– provided answer is ‘True’ or ‘False’
– another closely related function is .isdigit()
– difference between the two are the latter considering whether all chars incl in string are digits or not, e.g. ‘,.’ will give False
—| APPLICATION |—
go through individual chars in a for-loop
—| EXAMPLES |—
‘1234567890’.isdigit()
Out[2]: True
‘1234567890’.isdigit()
Out[2]: True
‘1234567890’.isnumeric()
Out[4]: True
‘1234.567890’.isnumeric()
Out[5]: False

Question 5

how to ask whether a value is alphanumeric?

Answer 5

]] < string >.isalpha( )
]] < string >.isalnum( )
]] < string >.isascii( )

• • all similar in use
• • I find the latest to be the most clarifying

Question 6

how to add different strings or chars together?

is it a built-in function?

Answer 6

1 - join
2 - no, it does not come up under built-in functions

]] .join( string/list/… )

e.g. from geeks for geeks
]] list1 = [ ‘1’,’2’,’3’,’4’ ]
]] s = ‘-‘
]] str_together = s.join( list1 )

Question 7

how to apply the same function to iterable values?

is it a built-in function?

Answer 7

1 - map
2 - yes, built-in function

]] result = map( fn, iteration )

# geeksforgeeks
# Python program to demonstrate working of map. 
# Return double of n 
def addition( n ): 
	return n + n 

# We double all numbers using map() 
numbers = ( 1, 2, 3, 4) 
result      = map( addition, numbers) 
print( list( result))

Question 8

how to find the char-number in the ascii charset?
reversely, how to the find the char from the ascii char-number?
are these built-in functions?

Answer 8

1 - ord()
]] ord( ‘a’ ) => 97
]] chr( 97 ) => a

– yes, these are built-in functions

Question 9

how to express/move chars from one charset to another?
is this a function?
how is it applied?

Answer 9

1 - decode
2 - no, this is not a function, it’s a method

# initializing string 
str = "geeksforgeeks"

# encoding string 
str_enc = str.encode( 'base64', 'strict' ) 

# printing the encoded string 
print "The encoded string in base64 format is : ", 
print str_enc 

# printing the original decoded string 
print "The decoded string is : ", 
print str_enc.decode( 'base64', 'strict' ) 

The encoded string in base64 format is : Z2Vla3Nmb3JnZWVrcw==

The decoded string is : geeksforgeeks

Question 10

how to list all functions for a module or class?
is this built-in?

Answer 10

1 - dir
2 - yes, this is a built-in function

]] dir( )

Question 11

how to divide in Python?

Answer 11

//
]] def div_10( upper_value )
]]     return upper_value // 10
]] print( div_10( 120 ) )
]]  12