Changing the capitalization of a string
Python’s string provides many functions that act on the capitalization of a string. These include:
- str.upper
- str.lower
- str.capitalize
- str.swapcase
str.upper()
str.upper takes every character in a string and converts it into its uppercase equivalent, for example:
print("TheCleverProgrammer".upper()) #Output THECLEVERPROGRAMMER
str.lower()
str.lower does the opposite , it takes every character in a string and converts it to its lowercase equivalent:
a = "THEcleverPROGRAmmer" print(a.lower()) #Output thecleverprogrammer
str.capitalize()
str.capitalize returns a capitalized version of the string, that is , it makes the first character have upper case and the rest lower:
a = "the CleVer pRogrammer" print(a.capitalize()) #Output The clever programmer
str.title()
str.title returns the title cased version of the string, that is every letter in the beginning of a word is made upper case and all others are made lower case:
a = "the CleVer pRogrammer" print(a.title()) #Output The Clever Programmer
str.swapcase()
str.swapcase() returns a new string object in which all lower case characters are swapped to upper case and all upper case characters to lower:
a = "the CleVer pRogrammer" print(a.swapcase()) #Output THE cLEvER PrOGRAMMER
Striping unwanted characters from a string
Three methods are provided that offer the ability to strip leading and trailing from a string:
- str.strip()
- str.rstrip()
- str.lstrip()
srt.strip()
str.strip acts on a given string and removes any leading or trailing characters contained in the argument characters, if characters is not supplied or is None, all white space characters are removed by default, for example:
print(" the clever programmer ".strip()) #Output the clever programmer
print(">>> the clever programmer".strip('>')) #Output the clever programmer
str.rstrip() and str.lstrip()
These methods have similar semantics and arguments with str.strip(), their difference lies in the direction from which they start.
str.rstrip() starts from the end of the string while str.lstrip() splits from the start of the string.
for example:
print(">>> the clever programmer >>>".rstrip('>')) #Output >>> the clever programmer print(">>> the clever programmer >>>".lstrip('>')) #Output the clever programmer >>>