python中的for循环
我在flask框架中有一个简单的for循环python中的for循环,python,flask,Python,Flask,我在flask框架中有一个简单的for循环 @app.route('/kde') def fetch_erga(): cur = mysql.connection.cursor() cur.execute("SELECT ergo FROM erga") rv = list(cur.fetchall()) for row in rv: stock = str(row[0]['ergo']) tsapr += [(stock)]
@app.route('/kde')
def fetch_erga():
cur = mysql.connection.cursor()
cur.execute("SELECT ergo FROM erga")
rv = list(cur.fetchall())
for row in rv:
stock = str(row[0]['ergo'])
tsapr += [(stock)]
return '<h2>' + tsapr + '</h2>'
我的意思是,它不是一个空光标。键错误通常与字典中缺少的键相关联。如果是我,我会开始研究strow[0]['ergo']。rv中的一个行对象是否可能没有“ergo”键 也许如果cur.executeSELECT ergo FROM erga返回一个空查询集 编辑:
rv中的每一行都是dict类型的对象,您正在引用行[0],但没有0键,请将stock=strrow[0]['ergo']更改为stock=strrow['ergo'],它应该可以工作您最好使用模板引擎本身:
谢谢你的回答。运行此命令:@app.route'/tyropitta'def tyri:cur=mysql.connection.cursor cur.execute'SELECT ergo from erga'rv=listcur.fetchall lista return+strrv[0]['ergo']+return+strrv+给我以下列表[{'ergo':u'52018'},{'ergo':u'52019'},{'ergo':u'63096700'},{'ergo':u'68003400'},{'ergo':u'68003501'},{'ergo':u'69003501'}]。因此选择光标不是空的…[{'ergo':u'52018'},{'ergo':u'52019'},{'ergo':u'63096700'},{'ergo':u'68003400'},{'ergo':u'68003501'},{'ergo':u'69003501'}]@app.route'/tyropitta'def tyri:cur=mysql.connection.cursor cur.execute'SELECT ergo from erga'rv=listcur.fetchall lista return+strrv[0]['ergo']+return+strrv+试着编辑你的问题,而不是评论,它的“不像一个符咒一样清晰可辨!”
@app.route('/kdef')
def fetch_ergas():
cur = mysql.connection.cursor()
cur.execute("SELECT ergo FROM erga")
rv = list(cur.fetchall())
return '<h2>' + str(rv) + '</h2>'
[{'ergo': u'52018'}, {'ergo': u'52019'}, {'ergo': u'63096700'}, {'ergo': u'68003400'}, {'ergo': u'68003501'}, {'ergo': u'69003501'}]