Comparing Strings

 Computer internally stores characters as numbers.

Every character has a unique Unicode value.

Ord

To find the Unicode value of a character, we use the

ord()

ord(character)

gives unicode value of the character.

Code

1

2

unicode_value = ord("A")

print(unicode_value)

PYTHON

Output

65

chr

To find the character with the given Unicode value, we use the

chr()

chr(unicode)

gives character with the unicode value.

Code

1

2

char = chr(75)

print(char)

PYTHON

Output

K

Unicode Ranges

48 - 57 -> Number Digits (0 - 9)

65 - 90 -> Capital Letters (A - Z)

97 - 122 -> Small Letters (a - z)

Rest -> Special Characters, Other Languages

Printing Characters

The below code will print the characters from

A

to

Z

Code

1

2

for unicode_value in range(65,91):

print(chr(unicode_value))

PYTHON

Output

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

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Comparing Strings

In Python, strings are compared considering unicode.

Code

1

print("A" < "B")

PYTHON

Output

True

As unicode value of

A

is 65 and

B

is 66, which internally compares

65 < 66

. So the output should be

True

Character by Character Comparison

In Python, String Comparison is done character by character.

Code

1

print("BAD" >= "BAT")

PYTHON

Output

False

Code

1

print("98" < "984")

PYTHON

Output

True

Best Practices

Naming Variables Rule #1

Use only the below characters

• Capital Letters ( A – Z )
• Small Letters ( a – z )
• Digits ( 0 – 9 )

• Underscore(_)

  Examples:
  age, total_bill

Naming Variables Rule #2

Below characters cannot be used

• Blanks ( )
• Commas ( , )
• Special Characters
  ( ~ ! @ # $ % ^ . ?, etc. )

Naming Variables Rule #3

Variable name must begin with

• Capital Letters ( A – Z )
• Small Letters ( a – z )
• Underscore( _ )

Naming Variables Rule #4

Cannot use Keywords, which are reserved for special meaning

• int
• str
• print
   etc.,

Keywords

Words which are reserved for special meaning

Code

1

help("keywords")

PYTHON

Output

Here is a list of the Python keywords. Enter any keyword to get more help.

False break for not

None class from or

True continue global pass

__peg_parser__ def if raise

and del import return

as elif in try

assert else is while

async except lambda with

await finally nonlocal yield

None

 

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Case Styles

• Camel case: totalBill
• Pascal case: TotalBill
• Snake case: total_bill

Snake case is preferred for naming the variables in Python.