Python program to count upper and lower case characters without using inbuilt functions

Given a string that contains both upper and lower case characters in it. The task is to count a number of upper and lower case characters in it.

Examples :

```Input : Introduction to Python
Output : Lower Case characters : 18
Upper case characters : 2

Input :  Welcome to GeeksforGeeks
Output : Lower Case characters : 19
Upper case characters: 3```

Python3

 `Str``=``"GeeksForGeeks"` `lower``=``0` `upper``=``0` `for` `i ``in` `Str``:` `      ``if``(i.islower()):` `            ``lower``+``=``1` `      ``else``:` `            ``upper``+``=``1` `print``(``"The number of lowercase characters is:"``,lower)` `print``(``"The number of uppercase characters is:"``,upper)`

Output

```The number of lowercase characters is: 10
The number of uppercase characters is: 3```

Time Complexity: O(n)
Auxiliary Space: O(1)

Explanation:

Here we are simply using the built-in method islower() and checking for lower case characters and counting them and in the else condition we are counting the number of upper case characters provided that the string only consists of alphabets.

Python3

 `# Python3 program to count upper and` `# lower case characters without using` `# inbuilt functions` `def` `upperlower(string):`   `    ``upper ``=` `0` `    ``lower ``=` `0`   `    ``for` `i ``in` `range``(``len``(string)):` `        `  `        ``# For lower letters` `        ``if` `(``ord``(string[i]) >``=` `97` `and` `            ``ord``(string[i]) <``=` `122``):` `            ``lower ``+``=` `1`   `        ``# For upper letters` `        ``elif` `(``ord``(string[i]) >``=` `65` `and` `            ``ord``(string[i]) <``=` `90``):` `            ``upper ``+``=` `1`   `    ``print``(``'Lower case characters = %s'` `%``lower,` `        ``'Upper case characters = %s'` `%``upper)`   `# Driver Code` `string ``=` `'GeeksforGeeks is a portal for Geeks'` `upperlower(string)`

Output

`Lower case characters = 27 Upper case characters = 3`

Time Complexity: O(n)
Auxiliary Space: O(1)

Explanation:

Here we are using the ord() method to get the ascii value of that particular character and then calculating it in the particular range.

Python3

 `s ``=` `"The Geek King"` `l,u ``=` `0``,``0` `for` `i ``in` `s:` `    ``if` `(i>``=``'a'``and` `i<``=``'z'``):` `        `  `        ``# counting lower case` `        ``l``=``l``+``1`                `    ``if` `(i>``=``'A'``and` `i<``=``'Z'``):` `        `  `        ``#counting upper case` `        ``u``=``u``+``1` `        `  `print``(``'Lower case characters: '``,l)` `print``(``'Upper case characters: '``,u)`

Output

```Lower case characters:  8
Upper case characters:  3```

Time Complexity: O(n)
Auxiliary Space: O(1)

Explanation:

Here we are iterating through the string and calculating upper and lower case characters using the ascii code range.

Python3

 `# Python3 program to count upper and` `# lower case characters without using` `# inbuilt functions` `string ``=` `'GeeksforGeeks is a portal for Geeks'` `upper ``=` `0` `lower ``=` `0` `up``=``"ABCDEFGHIJKLMNOPQRSTUVWXYZ"` `lo``=``"abcdefghijklmnopqrstuvwxyz"` `for` `i ``in` `string:` `    ``if` `i ``in` `up:` `        ``upper``+``=``1` `    ``elif` `i ``in` `lo:` `        ``lower``+``=``1` `print``(``'Lower case characters = %s'` `%``lower)` `print``(``'Upper case characters = %s'` `%``upper)`

Output

```Lower case characters = 27
Upper case characters = 3```

Time Complexity: O(n)
Auxiliary Space: O(1)

Explanation:

Here we have taken all the upper and lower case characters in separate strings and then count how many characters are present in individual strings.

Method #5 : Using operator.countOf() method

Python3

 `import` `operator as op` `Str` `=` `"GeeksForGeeks"` `lower ``=` `"abcdefghijklmnopqrstuvwxyz"` `l ``=` `0` `u ``=` `0` `for` `i ``in` `Str``:` `    ``if` `op.countOf(lower, i) > ``0``:` `        ``l ``+``=` `1` `    ``else``:` `        ``u ``+``=` `1` `print``(``"The number of lowercase characters is:"``, l)` `print``(``"The number of uppercase characters is:"``, u)`

Output

```The number of lowercase characters is: 10
The number of uppercase characters is: 3```

Time Complexity: O(n)

Space Complexity: O(1)

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