ãã©ã€ã¢ã³ã»ã«ãŒããã³ãšããã¹ã»ãªãããŒã«ããèæžãããã°ã©ãã³ã°èšèªCãïŒ1978幎ïŒä»¥æ¥ãããã°ã©ãã³ã°èšèªã®æåã®äŸãšããŠãæåå"Hello, World!"ãç»é¢ã«å°å·ããããã°ã©ã ããã䜿ãããŠããŸãããã®ç¿æ £ã«è¿åããŠãããã§ãPythonçã®HelloWorldããã°ã©ã ã®äžäŸã瀺ããŸãã
Python
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¥åããŠåäœã確èªããããšãã§ããŸãã
% python3
Python 3.9.4 (v3.9.4:1f2e3088f3, Apr 4 2021, 12:32:44)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> print ("Hello, World!")
Hello, World!
端æ«ã§python3
ã³ãã³ããå®è¡ãããšãpython3
ã®å
¥åããã³ãã>>>
ã衚瀺ãããŸãã
ããã§print("Hello, World!")
ãå
¥åããŠEnterããŒãæŒãã°ã端æ«ã«æåå "Hello, World!"ã衚瀺ãããŸãã
...
ããããã§ã¯ç¹°ãè¿ãäœåºŠã䜿ããããã°ã©ã ãšããŠã®HelloWorldããã°ã©ã ãã芧ããã ããŸãã
äœæããããã°ã©ã ãç¹°ãè¿ãäœåºŠã䜿ãããã«,ãããã°ã©ã ã¯ãã¡ã€ã«ã«ä¿åãã圢ã§çšæããŸãã
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# save this as hello.py
# è¡äžã®#以éã¯è¡æ«ãŸã§ã³ã¡ã³ããšãªã(Python ããã°ã©ã ã®å®è¡ã«åœ±é¿ããªã)
def Hello():
print( "Hello, World!" )
return
if __name__ == "__main__":
Hello()
Hello, World!
ãã®ããã°ã©ã ã®äžå¿éšåã¯def Hello():
ã§å§ãŸãäžè¡ã®ããã°ã©ã ã§ãã
ãã®äžè¡ã®ããã°ã©ã ã«ãã£ãŠãé¢æ°ãHello()
ãå®çŸ©ããŠããŸãã
def Hello(): # é¢æ°ã®å®çŸ©ã宣èš
print("Hello, World!") # é¢æ°ã®æ¬äœãã€ã³ãã³ãã«æ³šæ
return # é¢æ°åŒã³åºãã®çµäº
ãããã®è¡ãäžè¡ã¥ã€èª¬æããŠãããŸãã
def Hello():
ãŸããdef Hello():
ã§é¢æ°åãHello
ãšããé¢æ°ãå®çŸ©ããããšã宣èšããŠããŸãã
次ã®ã()
ã¯ãã®é¢æ°ã«ã¯åŒæ°ããªãããšã瀺ããŠããŸãã
:
ã¯ãã®åŸã«é¢æ°ã®æ¬äœãç¶ãããšã瀺ããŠããŸãã
#
ã¯ã³ã¡ã³ãã®éå§ã瀺ããŸããè¡æ«ãŸã§ãã³ã¡ã³ããšãªããŸãã
print("Hello, World!")
python3ã§ã¯printã¯ïŒæã§ã¯ãªãïŒé¢æ°ã§ãã åŒæ°ã«äžããããããŒã¿ãæååãšããŠã端æ«ã«è¡šç€ºããŸãã
return # é¢æ°åŒã³åºãã®çµäº
return # é¢æ°åŒã³åºãã®çµäº
次ã®return
æã¯ãã®è¡ãå®è¡ããããšé¢æ°åŒã³åºããçµäºããé¢æ°ãåŒã³åºãããšããããããã°ã©ã ã®å®è¡ãç¶ç¶ãããŸãã
ãã®return
æãã€ã³ãã³ããããŠããŸãã®ã§ãHello()
é¢æ°æ¬äœã®ãããã¯ã«å«ãŸããŠããŸãã
if __name__ == "__main__":
Hello()
Hello, World!
ç¶ãäºè¡ã®ããã°ã©ã ã¯ããã¡ã€ã«ã«pythonããã°ã©ã ãä¿åããéã«äœ¿ããããã䜿ãããè¡šçŸã§ãã ïŒããªãããããã®ãïŒãã¯åŸã§èª¬æããŸããïŒ
if
æã¯ãæäžã®æ¡ä»¶(ããã§ã¯__name__ == "__main__"
)ãæºè¶³ãããæãif
æã®æ¬äœ(ã€ã³ãã³ãã§åºå¥ãããäžé£ã®ããã°ã©ã æ, ããã§ã¯Hello()
)ãå®è¡ããŸããif
æã®ææ«ã¯:
ã§ãå®è¡ãã¹ããããã¯ãã€ã³ãã³ããããŠããããšã«æ³šæããŸãããã
__name__
ã¯Pythonã·ã¹ãã ãå©çšããå€æ°ã§ãname å±æ§ã¯ã¢ãžã¥ãŒã«ã®å®å
šä¿®é£Ÿåã«èšå®ãããªããã°ãªããŸããã ãšãªã£ãŠããŸãããpythonããã°ã©ã ãpython3ã³ãã³ãããèµ·åããããšã(åŸè¿°ïŒã¯"main"ã«èšå®ããããšããçŽæã«ãªã£ãŠããŸãã
def
æã䜿ããif
æã䜿ããdef
æãif
æã®äžèº«ã®ããã°ã©ã ã¯ãè¡é ãã€ã³ãã³ãããäœæããããã°ã©ã ãhello.py
ãšããååã®ãã¡ã€ã«ã«ä¿åããŸãã
ãã®ããã°ã©ã ãå®è¡ããã«ã¯ããã€ãã®æ¹æ³ããããŸãã
第äžã®æ¹æ³ã¯ãã·ã§ã«ã®ã³ãã³ãããããããpytho3(or py -3)ã³ãã³ãã䜿ã£ãŠå®è¡ããæ¹æ³ã§ãã
ãã¡ã€ã«hello.py
ãä¿åãããã£ã¬ã¯ããªã§ã
% python3 hello.py
ãå®è¡ããŸããšã
% python3 hello.py
Hello, World!
ã®ããã«ã端æ«ã«æååãå°å·ãããŸãã
ãã®ããã«åäœããã®ã¯ãhello.pyã«if __name__ == "__main__":
以äžã®ããã°ã©ã ãæžãããã ããšã«ãããã®ã§ãã
端æ«ããåãããã°ã©ã ãèµ·åããå¥ã®æ¹æ³ããããŸãã
pythonã¢ãžã¥ãŒã«ãçŽæ¥ã³ãã³ãã©ã€ã³ããèµ·åããæ¹æ³ã§ãã
%%bash
python3 -m hello
Hello, World!
-m
ã®ãã©ã¡ãŒã¿ã«ã¯python ã¢ãžã¥ãŒã«åãæå®ããŸããã.py
ãã€ããŠããªãããšã«ã泚æãã ããã
ãã®æ¹æ³ã¯ã¢ãžã¥ãŒã«ã®åäœç¢ºèªã®ãã¹ãããã°ã©ã ãå®è¡ãããããããã¯ãpip
ãªã©ã®ã¢ãžã¥ãŒã«ã®ããã«ã·ã§ã«ã¬ãã«ã®ã³ãã³ããšããŠãå©çšã§ããããã«ãããšãã®å¿çšããããŸãã
Linuxãmacosã§ã¯äœæããpythonããã°ã©ã ãã·ã§ã«ã³ãã³ããšããŠå®è¡ããããšãã§ããŸãã
%%bash
chmod +x hello.py
./hello.py
Hello, World!
chmod +x hello.py
ã¯äœæããPythonããã°ã©ã ãã¡ã€ã«ãã·ã§ã«ã³ãã³ããšããŠå®è¡å¯èœãšããããã®ããŸããªãã§ãã
hello.pyã®åé ã«
#!/usr/bin/env python3
ãããããšãå¿ èŠã§ãã
pythonããã°ã©ã ãå®è¡å¯èœãã¡ã€ã«ãšããããšã¯ãã»ãã¥ãªãã£ããŒã«ã«ãªãå¯èœæ§ããããŸãã®ã§ãæ éã«è¡ããŸãããã
ããããŠäœã£ãããã°ã©ã ãå¥ã®Pythonããã°ã©ã ãšããŠçµã¿åãããŠäœ¿ãããšã å¯èœã§ãã
% python3
python3
Python 3.9.6 (v3.9.6:db3ff76da1, Jun 28 2021, 11:49:53)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import hello
import hello
>>> hello.hello()
hello.hello()
Hello, World!
import
¶å¥ã®Pythonããã°ã©ã ã§HelloWorld.pyã®äžã®hello()é¢æ°ã䜿ãããã«ã
ãŸãHelloWorld
ããã°ã©ã ãPythonã¢ãžã¥ãŒã«ãšããŠimport
ããŸãã
import HelloWorld
ãã®æãHelloWorld.py
ã®if __name__ == "__main__":
ã®äžèº«ã¯å®è¡ãããªãããšã«æ³šæããŠãã ããã
import
ããHelloWorld
ã¢ãžã¥ãŒã«äžã®hello()
é¢æ°ã®å®è¡ã¯æ¬¡ã®ããã«èšè¿°ããŸãããã€ãŸãã¢ãžã¥ãŒã«åHelloWorld
ãšé¢æ°åhello
ã.
ã§ç¹ãã ååã§ã
HelloWorld
ã¢ãžã¥ãŒã«äžã®hello()
é¢æ°ãæå®ããŸãã
HelloWorld.hello()
Hello, World!
'Welcome to the World.'
Pythonããã°ã©ã äžã®é¢æ°ãšããŠå®è¡ããæã«ã¯ãé¢æ°ãè¿ããå€ã衚瀺ããŠããã®ã«æ³šæããŸãããã
(%%python3
ã¯jupyterlab ã®cell magicã§ããéåžžã®Pythonããã°ã©ã ã§ã¯äžèŠã§ããïŒ
%%python3
import HelloWorld
print(HelloWorld.hello())
Hello, World! Welcome to the World.
jupyterãããã¯jupyterlabã§ãã®è§£èª¬ãã芧ã®æ¹ã¯ã次ã®ã³ãŒããããã¯(ã»ã«ïŒãéžæããŠã
shift+EnterãããŒãæŒããŠã¿ãŠãã ããã åºåã®Hello World!
ãæŽæ°ãããã®ããåããã§ããããïŒ
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# save this as HelloWorld.py
"""
Python å
¥éè¬åº§ã第2åã®äŸé¡ããã°ã©ã
"""
_DEFALUT_RETURN_VALUE="Welcome to the World."
__DEFALUT_MSG="Hello, World!"
#ããã©ã«ãã®å€ã"Hello, World!"ã§ããåŒæ° msg ããã€é¢æ°ãhelloãå®çŸ©ããã
def hello(msg:str=__DEFALUT_MSG)->str:
"""
åŒæ°ãmsg(çç¥æã®å€ã¯"Hello, World") ã端æ«ã«åºåãã
"Welcome to the worldã"ãå€ãšããŠè¿ãã
"""
print(msg)
return _DEFALUT_RETURN_VALUE #é¢æ°ã®æ»ãå€ãšããŠ""Welcome to the World."ãè¿ãã
def test():
help(hello)
reply=hello()
print(reply)
if __name__ == "__main__":
test()
Help on function hello in module __main__: hello(msg: str = 'Hello, World!') -> str åŒæ°ãmsg(çç¥æã®å€ã¯"Hello, World") ã端æ«ã«åºåãã "Welcome to the worldã"ãå€ãšããŠè¿ãã Hello, World! Welcome to the World.
import hello; hello.hello
python3 -m hello
ããã°ã©ã ã§äœ¿ãããè²ã ãªåå(å€æ°åãé¢æ°åãã¯ã©ã¹åãã¢ãžã¥ãŒã«åã..)ã¯èå¥åãšåŒã°ããŸãã èå¥åã¯ããããã説æããã«åŸã£ãŠããã°èªç±ã«ã€ããããšãã§ããŸãã
ãšã¯ãããã®ã®ã åŸã§ããã°ã©ã ãåèªãããšãã«ããããã®èå¥åããããã®ã®æå³ããããããã«ååãã€ããŸãããã
èå¥åã¯ãã£ããèšã£ãŠã
-ãèå¥åã®æåã®æåã¯ã倧å°ã®ã¢ã«ãã¡ããã(a-zA-Z),ããããã¯ã¢ã³ããŒã¹ã³ã¢('_')ããèš±ãããã
ãšããã«ãŒã«ã«åŸããŸãã
äŸãã°ã
ãx y address _myname a0 a1
ãªã©ã¯ããããæå¹ãªåå(èå¥åïŒã§ãã
Python3ã§ã¯ããã« unicodeæå ã䜿ããŸããèå¥åãšããŠäœ¿ããunicodeæåã®ç¯å²ã«ã€ããŠã¯ãLanguage Referenceããã¥ã¢ã«ãã芧ãã ããã
ãšããããšã§ããããªããã°ã©ã ãæžãããšãã§ããŸãã
#!python3
# -*- coding: utf-8 -*-
def æšæ¶():
print("Hello, World!")
è¿äº= "ãããã,ããã£ããããŸãã"
return è¿äº
if __name__ == "__main__":
æšæ¶()
Hello, World!
æšæ¶()
Hello, World!
'ãããã,ããã£ããããŸãã'
ãšã¯ãããããããèŠãããŠããããã§ã¯ãããŸããã
python3ã®äºçŽèª
False await else import pass
None break except in raise
True class finally is return
and continue for lambda try
as def from nonlocal while
assert del global not with
async elif if or yield
ãããã®èå¥åã¯Pythonã§äºçŽãããŠãããããããŠãŒã¶ãŒãå®çŸ©ãããé¢æ°ïŒå€æ°ïŒã¯ã©ã¹ïŒã¢ãžã¥ãŒã«åãªã©ã«äœ¿ãããšã¯ã§ããŸããã
ãããã®äºçŽèªã¯Pythonã®åºæã®åèªãšããããšã§ãããããã®35åã®äºçŽèªã®äœ¿ãæ¹ããã¹ã¿ãŒããã°ãã©ããªPythonããã°ã©ã ãèªã¿ããªãããšãå¯èœã§ãïŒåççã«ã¯ïŒããç°¡åã§ãããïŒã^_^
è足ã§ãããäºçŽèªã®ä»ã«ãèšå·ãã~!@#%^&*()-+/={}[]|:;\"'<>.,ããã®äœ¿ãæ¹ãåŠç¿ããå¿ èŠããããŸãã
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åŸè ã¯äžèº«ã®æååã«æ¹è¡ãå«ãã§ããŠãè¯ããããªãã¡äžèº«ã®æååãè€æ°è¡ã«ãŸããã£ãŠããŠããããšãããšããã倧ããªéãã§ãã
ãªããPythonã®æååã¯Cèšèªã®ãããšç°ãªãã·ã³ã°ã«ã¯ã©ãŒãã'ãã䜿ã£ãæååãšããã«ã¯ã©ãŒããâãã䜿ã£ãæååã«æå³çãªéãã¯ãããŸããã
ãŸããPythonã®æååã¯Unicodeã®æåã®äžŠã³ã§ããCèšèªã®æååã«çžåœãããã®ã¯ãbytes
ãããã¯bytearray
ã§ããïŒè©³çŽ°ã¯ãŸãå¥ã®æ©äŒã«...)
æååã«ã€ããŠã¯ã次å以éã®è¬åº§ã§ãã詳ãã説æããŸãã
docstring
を使おう。¶ãã¡ã€ã«ã®åé ãé¢æ°å®çŸ©ã®åé ã«çœ®ãããæååããŒã¿ã¯docstring
ãšåŒã°ããŸããã
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ããã°ã©ã ãïŒèªãïŒéã«åœ¹ç«ã¡ãŸãããdocstring
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help()
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ã®äžèº«ã端æ«çã«åºåãããŸãã
#!python3
# -*- coding: utf-8 -*-
# save this as HelloWorld.py
#
"""
Python å
¥éè¬åº§ã第2åã®äŸé¡ããã°ã©ã
"""
_DEFALUT_RETURN_VALUE="Welcome to the World."
__DEFALUT_MSG="Hello, World!"
def hello(msg:str=__DEFALUT_MSG)->str:
"""
åŒæ°ãmsg(çç¥æã®å€ã¯"Hello, World") ã端æ«ã«åºåãã
"Welcome to the worldã"ãå€ãšããŠè¿ãã
"""
print(msg)
return _DEFALUT_RETURN_VALUE
def test():
help(hello)
reply=hello()
print(reply)
if __name__ == "__main__":
test()
Help on function hello in module __main__: hello(msg: str = 'Hello, World!') -> str åŒæ°ãmsg(çç¥æã®å€ã¯"Hello, World") ã端æ«ã«åºåãã "Welcome to the worldã"ãå€ãšããŠè¿ãã Hello, World! Welcome to the World.
def <é¢æ°å> (<åŒæ°ã®ãªã¹ã>):
ã®æ§æã䜿ãããif <æ¡ä»¶> :
ã®æ§æã䜿ãã<æ¡ä»¶>
ã®è«çåŒãšããŠã®å€ãFalse
ã§ãªããšããç¶ãã³ãŒããããã¯ãå®è¡ãããããããç¡äºã«æåã®äžæ©ã¯èžã¿åºããã§ããããïŒã次ã¯ã©ãã«åãããŸããããïŒ
è足ïŒ
import this
ã®ZenãšåãããŠYodaã«åž°ãããããšããã次ã®æ ŒèšãèŠããŠãããŸãããã
Yoda:.. If once you start down the dark path, forever will it dominate your destiny, consume you it will.
...
Yoda:ãYou will know. When your code you try to read six months from now.
åºåããã¡ãã»ãŒãžã«ãã¡ãã»ãŒãžã®åãæã®ååãå ããŠã¿ãŸãããã
åŒæ°ãšããŠã¡ãã»ãŒãžã®åããŠã®ååãåãä»ãããæ°ããé¢æ°ã HelloTo
ãå®çŸ©ããŠã¿ãŸãããã
"""
åŒæ°ããã€é¢æ°ã®å®çŸ©ã®äŸ
åç¬ã®ã¹ã¯ãªããããŠå®è¡ãããæã«ã¯ãæšæºã®ã¢ãžã¥ãŒã«getpassã䜿ã£ãŠãŠãŒã¶ã®ååãåãåºããŠäœ¿ãã
"""
def HelloTo(name:str)->bool:
"""
åŒæ°nameã«äžããããååã®æååã䜿ã£ãŠãã°ãªãŒãã£ã³ã° ã¡ãã»ãŒãžã端æ«ã«è¡šç€ºããã
"""
print("Hello {}!".format(name))
print("Welcome to the Python world!!")
return True
import getpass # getpass ã¢ãžã¥ãŒã«ã import = ã¢ãžã¥ãŒã«ã®æäŸããé¢æ°ãªã©ã䜿ããããã«ããã
def main():
username=getpass.getuser() # getpassã¢ãžã¥ãŒã«ã®getuser()é¢æ°ã䜿ã£ãŠãusernameãååŸããã
HelloTo(username)
if __name__ == "__main__":
main()
Hello noboru! Welcome to the Python world!!
é¢æ°ã®åŒæ°ã«å€ãäžããŠå®è¡ããŠèŠãŸãã
HelloTo("Albert")
HelloTo(name="Einstein")
main()
Hello Albert! Welcome to the Python world!! Hello Einstein! Welcome to the Python world!! Hello noboru! Welcome to the Python world!!
print()
é¢æ°ã¯è€æ°ã®åŒæ°ãåãåã£ãæãæž¡ãããããŒã¿åã«å¿ããŠæŽåœ¢ããæååã端æ«ã«åºåããŸãã
åºåãããæååããã现ããå¶åŸ¡ããããã«ã¯æååããŒã¿ã®.format
ã¡ãœããã䜿ããŸãã
(Python2ãšã®äºææ§ã®ããã«ãå¥ã®æ¹æ³(""%
)ããµããŒããããŠããŸããã
.format
ã¡ãœãããpython3ã§ã®æšæºçãªæ¹æ³ã§ãã)
print("Hello {}!".format(name))
æååå®æ°äžã«æ¹è¡ã³ãŒããªã©ãæ¿å
¥ããã«ã¯ãCèšèªãšåãããã«ããšã¹ã±ãŒãæå\
ãã€ãã£ããšã¹ã±ãŒãæåå®æ°ã䜿ããŸãã