TheDeveloperBlog.com

Home | Contact Us

C-Sharp | Java | Python | Swift | GO | WPF | Ruby | Scala | F# | JavaScript | SQL | PHP | Angular | HTML

<< Back to PYTHON

Python Lower and Upper: Capitalize String

Use the lower, upper, islower and isupper methods. Call title and capitalize.
Lower, upper. All letters are either lowercase or uppercase. We can change the case of characters in Python with the lower and upper methods.
String casing. More powerful methods such as capitalize and title() also exist. We cover the basic methods (upper and lower) first, and then explore isupper and islower.
An example. Often we need to uppercase (or lowercase) strings. With the upper and lower methods, we apply the needed transformations. These methods do not affect non-letter characters.

Tip: We never need to call upper() on a string that is already uppercased. Please see the isupper and islower methods.

Python program that uses upper, lower value = "Tree" # Uppercase the string. x = value.upper() print(x) # Lowercase the string. y = value.lower() print(y) Output TREE tree
Isupper, islower. Is a string already uppercase or lowercase? We can tell this easily with the isupper and islower methods. These two methods are often used with if-statements.

Also: Please see the performance test. Is lower is used to improve speed. With it, we can avoid copying strings.

Python program that uses isupper, islower value1 = "ABC123" value2 = "abc123" # Method can be used in an if-statement. if value1.isupper(): print(1) # Call methods on both strings. print(value1.isupper()) print(value2.isupper()) print(value1.islower()) print(value2.islower()) Output 1 True False False True
Capitalize. This method affects only the first letter in a string. It changes it to be uppercase. If the first character is not a letter, nothing happens.

Here: Please notice that the variable "s" is assigned to the result of capitalize().

Tip: This means capitalize() does not change the existing string in-place. It creates a new copy of the string in memory and returns that.

Python program that uses capitalize # An input string. s = "Codex" # Capitalize and assign. s = s.capitalize() print(s) Output Perls
Title. Strings have a title method. This method is not smart. But it does help with many common strings. It capitalizes each word in a string.

Warning: Title will capitalize words that are not supposed to be capitalized, like "of" and "and."

Thus: A custom implementation (not the title method) would be needed if your requirements are more complex.

Python program that uses title string method value = "the unbearable lightness of being" # Convert to title case. result = value.title() print(result) Output The Unbearable Lightness Of Being
Istitle. This is a less-useful method. It scans a string and determines if the string has capital letters for each word. It can be used to avoid calling title() on strings.

Note: As with the title method, istitle will become confused on certain words. It requires all words, even "and" to be capitalized.

Python program that uses istitle value1 = "A Car" value2 = "A car" value3 = "a Car" value4 = "A123" value5 = "a123" # Test istitle method. print(value1.istitle()) print(value2.istitle()) print(value3.istitle()) print(value4.istitle()) print(value5.istitle()) Output True False False True False
Benchmark, lower. The islower method can be used as an optimization. Before calling lower() we can check whether the string is already lowercase.

Version 1: This version of the code calls the lower() method on every iteration through the loop.

Version 2: This version uses islower() before calling lower(). It never calls lower() because the string is already lowercase.

Result: The code that checks islower() first is faster. This optimization will only work if your data is usually lowercase.

Python program that benchmarks islower, lower import time value = "intuitive" print(time.time()) # Version 1: lower. i = 0 while i < 10000000: v = value.lower() i += 1 print(time.time()) # Version 2: islower and lower. i = 0 while i < 10000000: if not value.islower(): v = value.lower() i += 1 print(time.time()) Output 1384626116.650 1384626122.033 lower(): 5.38 s 1384626124.027 islower() and lower(): 1.99 s
Lower dictionary. We can use a dictionary to avoid lowercasing the same string many times. This can speed up the lowercase operation—the cache may be 10 times faster.Lower Dictionary
A summary. Text processing often involves normalizing the casing of strings. With the lower method and its friend upper(), we do this.
Testing cases. Performance is improved in many programs by using islower() and isupper(). This reduces work but may introduce complexity.Strings
© TheDeveloperBlog.com
The Dev Codes

Related Links:


Related Links

Adjectives Ado Ai Android Angular Antonyms Apache Articles Asp Autocad Automata Aws Azure Basic Binary Bitcoin Blockchain C Cassandra Change Coa Computer Control Cpp Create Creating C-Sharp Cyber Daa Data Dbms Deletion Devops Difference Discrete Es6 Ethical Examples Features Firebase Flutter Fs Git Go Hbase History Hive Hiveql How Html Idioms Insertion Installing Ios Java Joomla Js Kafka Kali Laravel Logical Machine Matlab Matrix Mongodb Mysql One Opencv Oracle Ordering Os Pandas Php Pig Pl Postgresql Powershell Prepositions Program Python React Ruby Scala Selecting Selenium Sentence Seo Sharepoint Software Spellings Spotting Spring Sql Sqlite Sqoop Svn Swift Synonyms Talend Testng Types Uml Unity Vbnet Verbal Webdriver What Wpf