如何讓你的Python程序支持多語言

如何讓你的Python程序支持多語言

本文介紹如何經過Python標準庫gettext幫助你的程序支持多語言。

代碼例子

import random

guessesTaken = 0

print(_("Hello! What's your name?"))
myName = input()

number = random.randint(1, 20)
print("Well, {}, I am thinking of a number between 1 and 20.".format(myName))

while guessesTaken < 6:
    print("Take a guess.")
    guess = input()
    try:
        guess = int(guess)
    except ValueError:
        print("You should give me a number.")
        continue

    if guess < number:
        print("Your guess is too low.")

    if guess > number:
        print("You guess is too high.")

    if guess == number:
        break

if guess == number:
    print("Good job, {}! You guessed my number in {} guesses!".format(
        myName, guessesTaken))

if guess != number:
    print("Nope. The number I was thinking of was {}.".format(number))

這是咱們一個簡單的猜數字遊戲，咱們執行看看過程。

$ python3 guess.py 
Hello! What's your name?
Aidan
Well, Aidan, I am thinking of a number between 1 and 20.
Take a guess.
13
You guess is too high.
Take a guess.
2
Your guess is too low.
Take a guess.
12
You guess is too high.
Take a guess.
1
Your guess is too low.
Take a guess.
10
You guess is too high.
Take a guess.
9
Good job, Aidan! You guessed my number in 6 guesses!

程序是很漂亮了，但是老闆忽然要求你改爲中文的，那麼咱們一般可能選擇將字符串所有修改成相應中文，可是老闆要讓你本身針對不一樣用戶不一樣語言就麻煩了。那有啥辦法呢？Python標準庫gettext能夠幫助咱們。

改造

咱們首先用_()，然改造咱們的字符串。你能夠把_()想象成相似以下函數

def _(s):
    spanishStrings = {'Hello world!': 'Hola Mundo!'}
    frenchStrings = {'Hello world!': 'Bonjour le monde!'}
    germanStrings = {'Hello world!': 'Hallo Welt!'}

    if LANGUAGE == 'English':
        return s
    if LANGUAGE == 'Spanish':
        return spanishStrings[s]
    if LANGUAGE == 'French':
        return frenchStrings[s]
    if LANGUAGE == 'German':
        return germanStrings[s]

不過，當我查看他類型時，我發現他應該是某種繼承了list的擴展類型。

>>> type(_)
<class 'list'>

改造後咱們的代碼以下

import random

guessesTaken = 0

print(_("Hello! What's your name?"))
myName = input()

number = random.randint(1, 20)
print(_("Well, {}, I am thinking of a number between 1 and 20.").format(myName))

while guessesTaken < 6:
    guessesTaken += 1
    print(_("Take a guess."))
    guess = input()
    try:
        guess = int(guess)
    except ValueError:
        print(_("You should give me a number."))
        continue

    if guess < number:
        print(_("Your guess is too low."))

    if guess > number:
        print(_("You guess is too high."))

    if guess == number:
        break

if guess == number:
    print(_("Good job, {}! You guessed my number in {} guesses!").format(
        myName, guessesTaken))

if guess != number:
    print(_("Nope. The number I was thinking of was {}.").format(number))

提取字符串

Python 自帶一個工具咱們提取使用_()包裹的字符串

pygettext3 -d guess guess.py

它生成了以下文件：

$ cat guess.pot 
# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR ORGANIZATION
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"POT-Creation-Date: 2014-12-24 15:35+CST\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Generated-By: pygettext.py 1.5\n"


#: guess.py:5
msgid "Hello! What's your name?"
msgstr ""

#: guess.py:9
msgid "Well, {}, I am thinking of a number between 1 and 20."
msgstr ""

#: guess.py:12
msgid "Take a guess."
msgstr ""

#: guess.py:17
msgid "You should give me a number."
msgstr ""

#: guess.py:21
msgid "Your guess is too low."
msgstr ""

#: guess.py:24
msgid "You guess is too high."
msgstr ""

#: guess.py:30
msgid "Good job, {}! You guessed my number in {} guesses!"
msgstr ""

#: guess.py:34
msgid "Nope. The number I was thinking of was {}."
msgstr ""

翻譯工做

咱們經過使用poedit這個很是好用的工具對其翻譯成咱們想要的目標文件，該工具還帶有翻譯詞典，跨平臺。地址：http://poedit.net/

翻譯後的結果

翻譯後生成

guess.po

# SOME DESCRIPTIVE TITLE.
# Copyright (C) YEAR ORGANIZATION
# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.
#
msgid ""
msgstr ""
"Project-Id-Version: \n"
"POT-Creation-Date: 2014-12-24 15:35+CST\n"
"PO-Revision-Date: 2014-12-24 16:23+0800\n"
"Last-Translator: \n"
"Language-Team: \n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"Generated-By: pygettext.py 1.5\n"
"X-Generator: Poedit 1.7.1\n"
"Plural-Forms: nplurals=1; plural=0;\n"
"Language: zh\n"

#: guess.py:5
msgid "Hello! What's your name?"
msgstr "你好！你叫什麼名字？"

#: guess.py:9
msgid "Well, {}, I am thinking of a number between 1 and 20."
msgstr "好的，{}，我內心想了個1到20之間的數。"

#: guess.py:12
msgid "Take a guess."
msgstr "猜猜看。"

#: guess.py:17
msgid "You should give me a number."
msgstr "你應該給我個數字。"

#: guess.py:21
msgid "Your guess is too low."
msgstr "你猜低了。"

#: guess.py:24
msgid "You guess is too high."
msgstr "你猜高了。"

#: guess.py:30
msgid "Good job, {}! You guessed my number in {} guesses!"
msgstr "漂亮，{}！你用了{}次猜中了個人數字。"

#: guess.py:34
msgid "Nope. The number I was thinking of was {}."
msgstr "不對。我想的數字是{}。"

還有一個mo擴展的文件，MO 文件是面向計算機的、由 PO 文件經過 gettext 軟件包編譯而成的二進制文件。

咱們以下放置這兩個文件

├── guess.py
├── locale
│ └── zh_CN
│ └── LC_MESSAGES
│ ├── guess.mo
│ └── guess.po

武裝gettext

而後咱們在代碼加入

import gettext

es = gettext.translation('guess', localedir='locale', languages=['zh_CN'])
es.install()

終極版本

import random
import gettext

es = gettext.translation('guess', localedir='locale', languages=['zh_CN'])
es.install()

guessesTaken = 0

print(_("Hello! What's your name?"))
myName = input()

number = random.randint(1, 20)
print(_("Well, {}, I am thinking of a number between 1 and 20.").format(myName))

while guessesTaken < 6:
    guessesTaken += 1
    print(_("Take a guess."))
    guess = input()
    try:
        guess = int(guess)
    except ValueError:
        print(_("You should give me a number."))
        continue

    if guess < number:
        print(_("Your guess is too low."))

    if guess > number:
        print(_("You guess is too high."))

    if guess == number:
        break

if guess == number:
    print(_("Good job, {}! You guessed my number in {} guesses!").format(
        myName, guessesTaken))

if guess != number:
    print(_("Nope. The number I was thinking of was {}.").format(number))

驚人結果

$ python3 guess.py 
你好！你叫什麼名字？
大熊
好的，大熊，我內心想了個1到20之間的數。
猜猜看。
10
你猜高了。
猜猜看。
8
你猜高了。
猜猜看。
6
你猜高了。
猜猜看。
4
漂亮，大熊！你用了4次猜中了個人數字。

結論

Python 在國際化操做方面很簡單，你是否有更好的方案？