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This article introduces the relevant knowledge of "what are the methods of Python text processing". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Initials are capitalized

For strings made up of English words, most of the time, we need to capitalize the first letters of English. If we do not understand its efficient function, we usually use a loop to judge the space, take the letter after the space, judge its coding in ASCII, and replace the string in that position with its uppercase.

However, there is a function in python3 that capitalizes the first letter directly, which is capwords (). Next, let's implement an uppercase string change with a small piece of code.

Import strings = "When he shewed the riches of his glorious kingdom and the honour of his excellent majesty many days, even an hundred and fourscore days" print ("original string") print (s) result = string.capwords (s) print ("first letter uppercase string") print (result) string template

In the string library, the string template function is string.Template (), which can be used to concatenate strings. The sample code is as follows:

Import stringvalues = {"name": "liyuanjing", "age": "13",} s = "" My name is: $name I am $age years old "template_str = string.Template (s) print (template_str.substitute (values)

Here, we use the string template string.Template, and then use the function substitute () to replace the string.

However, what if there is no corresponding key in the values dictionary when it is possible to replace it? The string library also provides us with a function safe_substitute ().

Import stringvalues = {"name": "liyuanjing", "age": "13",} s = "My name is: $name I am $age years old $work" template_str = string.Template (s) print (template_str.safe_substitute (values)

Because the dictionary does not have a corresponding value to replace, the original string data is retained.

Advanced template

The template above is used by the rule system provided by default in the string library. In fact, we can also customize the matching method of the template. The specific code is as follows:

Import stringclass MyTemplate (string.Template): delimiter ='@ 'idpattern =' [amurz] + _ [0-9] + 'values = {"name_1": "liyuanjing", "age_1": "13",} s = "My name is: @ name_1 I am @ age_1 years old @ work_1"template_str = MyTemplate (s) print (template_str.safe_substitute (values))

Here, delimiter represents the symbol that needs to be matched, and the default symbol "$" is replaced by'@'by the blogger. Second, idpattern is the key name rule for values, which is specified in regular expressions, such as "string _ number".

Format usage

Basic usage

Anyone who has a basic knowledge of other languages should be more or less exposed to format string substitution. Here, let's take a direct look at the basic ways to use it:

Print ("My name is {}" .format ("liyuanjing")) # curly braces match, fill print ("My {1} is {0}" .format ("liyuanjing", "name")) # numeric matching sequentially, fill print ("My {name} is {tom}" .format (tom= "liyuanjing", name= "name")) # keyword matching by position, and fill in advanced usage by keyword

The format function can not only match the replacement string, but also use it to match its text, or take a few decimal places, and so on. Next, let's take a look at how these uses are implemented.

Print ('{} and {} '.format (' tom', 'Jerry')) print (' {: 10s} '.format (' *')) # default left alignment print ('{: > 10s} '.format (' *')) # right alignment print ('{: ^ 10s} '.format (' *')) # middle alignment print ('{:

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