python - 为什么当我激活 virtualenv 时我的提示符没有改变？

Question

当我使用 workon 激活 Python virtualenv 时，我的提示符不会更改以识别环境。

我已确认我的 activate 脚本包含

if [ -z "${VIRTUAL_ENV_DISABLE_PROMPT-}" ] ; then
    _OLD_VIRTUAL_PS1="$PS1"
    if [ "x" != x ] ; then
        PS1="$PS1"
    else
        PS1="(`basename \"$VIRTUAL_ENV\"`) $PS1"
    fi
    export PS1
fi

并且 VIRTUAL_ENV_DISABLE_PROMPT 未设置。

为什么会发生这种情况以及我可以采取什么措施来解决它？

<小时/>

GNU bash，版本 3.2.57(1)-release (x86_64-apple-darwin15)

<小时/>

我的 .bash_profile 中正在进行一些奇特的步法，但我不明白为什么一旦设置了提示，这些都会很重要:

declare PSCOLORPATH='\[\e[0;33m\]'
declare PSCOLORPROMPT='\[\e[1;32m\]'
declare PSCOLORHOST='\[\e[0;32m\]'
declare PSCOLOROOT='\[\e[1;31m\]'
declare PSCOLOREND='\[\e[m\]'
#echo $PSCOLORPATH
if [ $SSH_FLAG -eq 1 ] ; then
    declare PSHOST='\h:'
else
    declare PSHOST=''
fi
if [ $IS_SU -eq 1 ] ; then
    PS1_INFO="$PSCOLOROOT[SU] $PSCOLORHOST$PSHOST$PSCOLORPATH\w"
else
    PS1_INFO="$PSCOLORHOST$PSHOST$PSCOLORPATH\w"
fi
PS1_PROMPT="$PSCOLORPROMPT \\$ $PSCOLOREND"
declare -x PS1="$PS1_INFO$PS1_PROMPT"
#declare -x PS1="$PSCOLORHOST$PSHOST$PSCOLORPATH\w $PSCOLORPROMPT\\$ $PSCOLOREND"
declare -x PS2="$PSCOLORPROMPT> $PSCOLOREND"
declare -x PS4="$PSCOLORPROMPT+ $PSCOLOREND"

source $(brew --repository)/etc/bash_completion.d/git-prompt.sh

GIT_PS1_HIDE_IF_PWD_IGNORED=1
PS1_NORMAL=$PS1
_gitprompt () {
    if [ "$1" = "off" ]; then
        GIT_PS1_SHOWUPSTREAM=; GIT_PS1_SHOWDIRTYSTATE=; GIT_PS1_SHOWUNTRACKEDFILES=; GIT_PS1_SHOWCOLORHINTS=;
        PS1="$PS1_NORMAL"; PROMPT_COMMAND=; 
    else
        if [ "$1" = "verbose" ]; then
            GIT_PS1_SHOWUPSTREAM="auto"; GIT_PS1_SHOWDIRTYSTATE=1; GIT_PS1_SHOWUNTRACKEDFILES=1; GIT_PS1_SHOWCOLORHINTS=;
            PROMPT_COMMAND='__git_ps1 "$PS1_INFO" "$PS1_PROMPT"';           
        elif [ "$1" = "color" ]; then
            GIT_PS1_SHOWUPSTREAM=; GIT_PS1_SHOWDIRTYSTATE=; GIT_PS1_SHOWUNTRACKEDFILES=; GIT_PS1_SHOWCOLORHINTS=1;
            PROMPT_COMMAND='__git_ps1 "$PS1_INFO$PSCOLOREND" "$PS1_PROMPT"';            
        else
            GIT_PS1_SHOWUPSTREAM=; GIT_PS1_SHOWDIRTYSTATE=; GIT_PS1_SHOWUNTRACKEDFILES=; GIT_PS1_SHOWCOLORHINTS=;
            PROMPT_COMMAND='__git_ps1 "$PS1_INFO" "$PS1_PROMPT"';
        fi
    fi
}
alias gitprompt="_gitprompt"

gitprompt verbose

<小时/>

FWIW，设置-x；源/path/to/activate 给出:

+ __git_ps1 '\[\e[0;32m\]\[\e[0;33m\]\w' '\[\e[1;32m\] \$ \[\e[m\]'
+ local exit=126
+ local pcmode=no
+ local detached=no
+ local 'ps1pc_start=\u@\h:\w '
+ local 'ps1pc_end=\$ '
+ local 'printf_format= (%s)'
+ case "$#" in
+ pcmode=yes
+ ps1pc_start='\[\e[0;32m\]\[\e[0;33m\]\w'
+ ps1pc_end='\[\e[1;32m\] \$ \[\e[m\]'
+ printf_format=' (%s)'
+ PS1='\[\e[0;32m\]\[\e[0;33m\]\w\[\e[1;32m\] \$ \[\e[m\]'
+ local ps1_expanded=yes
+ '[' -z '' ']'
+ '[' -z '3.2.57(1)-release' ']'
+ shopt -q promptvars
+ local repo_info rev_parse_exit_code
+ git rev-parse --git-dir --is-inside-git-dir --is-bare-repository --is-inside-work-tree --short HEAD
+ repo_info=
+ rev_parse_exit_code=128
+ '[' -z '' ']'
+ return 126
~ $ set -x; source ~/Documents/Projects/Coding/Python/venvs/zoot/bin/activate
+ set -x
+ source /Users/Rax/Documents/Projects/Coding/Python/venvs/zoot/bin/activate
+ deactivate nondestructive
+ unset -f pydoc
+ '[' -z _ ']'
+ PATH=/Users/Rax/.cabal/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/Rax/bin:/opt/X11/bin:/Library/TeX/texbin
+ export PATH
+ unset _OLD_VIRTUAL_PATH
+ '[' -z '' ']'
+ '[' -n /bin/bash ']'
+ hash -r
+ '[' -z _ ']'
+ PS1='\[\e[0;32m\]\[\e[0;33m\]\w\[\e[1;32m\] \$ \[\e[m\]'
+ export PS1
+ unset _OLD_VIRTUAL_PS1
+ unset VIRTUAL_ENV
+ '[' '!' nondestructive = nondestructive ']'
+ VIRTUAL_ENV=/Users/Rax/Documents/Projects/Coding/Python/venvs/zoot
+ export VIRTUAL_ENV
+ _OLD_VIRTUAL_PATH=/Users/Rax/.cabal/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/Rax/bin:/opt/X11/bin:/Library/TeX/texbin
+ PATH=/Users/Rax/Documents/Projects/Coding/Python/venvs/zoot/bin:/Users/Rax/.cabal/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/Rax/bin:/opt/X11/bin:/Library/TeX/texbin
+ export PATH
+ '[' -z '' ']'
+ '[' -z '' ']'
+ _OLD_VIRTUAL_PS1='\[\e[0;32m\]\[\e[0;33m\]\w\[\e[1;32m\] \$ \[\e[m\]'
+ '[' x '!=' x ']'
+ basename /Users/Rax/Documents/Projects/Coding/Python/venvs/zoot
+ PS1='(zoot) \[\e[0;32m\]\[\e[0;33m\]\w\[\e[1;32m\] \$ \[\e[m\]'
+ export PS1
+ alias pydoc
+ '[' -n /bin/bash ']'
+ hash -r
+ __git_ps1 '\[\e[0;32m\]\[\e[0;33m\]\w' '\[\e[1;32m\] \$ \[\e[m\]'
+ local exit=0
+ local pcmode=no
+ local detached=no
+ local 'ps1pc_start=\u@\h:\w '
+ local 'ps1pc_end=\$ '
+ local 'printf_format= (%s)'
+ case "$#" in
+ pcmode=yes
+ ps1pc_start='\[\e[0;32m\]\[\e[0;33m\]\w'
+ ps1pc_end='\[\e[1;32m\] \$ \[\e[m\]'
+ printf_format=' (%s)'
+ PS1='\[\e[0;32m\]\[\e[0;33m\]\w\[\e[1;32m\] \$ \[\e[m\]'
+ local ps1_expanded=yes
+ '[' -z '' ']'
+ '[' -z '3.2.57(1)-release' ']'
+ shopt -q promptvars
+ local repo_info rev_parse_exit_code
+ git rev-parse --git-dir --is-inside-git-dir --is-bare-repository --is-inside-work-tree --short HEAD
+ repo_info=
+ rev_parse_exit_code=128
+ '[' -z '' ']'
+ return 0

Answer 1

在您的.bash_profile中，您正在调用gitprompt verbose，而该设置又是:

PROMPT_COMMAND='__git_ps1 "$PS1_INFO" "$PS1_PROMPT"'

我不知道 __git_ps1 是什么，但是从 set -x; 的输出来看来源...我可以看出它是罪魁祸首:

+ hash -r  # <<< This is the last command executed by the 'activate' script
+ __git_ps1 '\[\e[0;32m\]\[\e[0;33m\]\w' '\[\e[1;32m\] \$ \[\e[m\]'  # <<< This is PROMPT_COMMAND being called
...
+ PS1='\[\e[0;32m\]\[\e[0;33m\]\w\[\e[1;32m\] \$ \[\e[m\]'  # <<< This is PS1 getting restored
...

这里有几个选项，请选择您喜欢的一个:

• 修改activate并添加一行以取消设置PROMPT_COMMAND;
• 修改 __git_ps1(如果可以的话)，以便在设置 VIRTUAL_ENV 时它不会触及 PS1；
• 如果您无法修改 __git_ps1，则在其周围编写一个包装器；
• 在进入 virtualenv 之前手动取消设置 PROMPT_COMMAND；
• 避免在 .bash_profile 中调用 gitprompt。